Class used to pass input/output arguments to C functions generated by MATLAB Compiler SDK
Use the mwArray class to pass input/output
arguments to generated C++ interface functions. This class consists
of a thin wrapper around a MATLAB® array. All data in MATLAB is
represented by matrices. The mwArray class provides
the necessary constructors, methods, and operators for array creation
and initialization, as well as simple indexing.
Note: Arithmetic operators, such as addition and subtraction, are no longer supported as of Release 14. |
mclcppclass.h
mclmcrrt.h
Tip MATLAB Compiler SDK™ automatically includes these header files in the header file generated for your MATLAB functions. |
Construct empty array of type mxDOUBLE_CLASS.
Construct empty array of specified type.
mxClassID mxID | Valid mxClassID specifying the type of array
to construct. See the Work with mxArrays for more information on mxClassID. |
Create a 2–D matrix of the specified type and complexity.
For numeric types, the matrix can be either real or complex. For numeric
types, pass mxCOMPLEX for the last argument to
create a complex matrix. All elements are initialized to zero. For
cell matrices, all elements are initialized to empty cells.
mwSize num_rows | Number of rows in the array |
mwSize num_cols | Number of columns in the array |
mxClassID mxID | Valid mxClassID specifying the type of array
to construct. See the Work with mxArrays for more information on mxClassID. |
mxComplexity cmplx | Complexity of the array to create. Valid values are mxREAL and mxCOMPLEX.
The default value is mxREAL. |
Create an n-dimensional array of the specified
type and complexity. For numeric types, the array can be either real
or complex. For numeric types, pass mxCOMPLEX for
the last argument to create a complex matrix. All elements are initialized
to zero. For cell arrays, all elements are initialized to empty cells.
mwSize num_dims | Number of dimensions in the array |
const | Dimensions of the array |
mxClassID mxID | Valid mxClassID specifying the type of array
to construct. See the Work with mxArrays for more information on mxClassID. |
mxComplexity cmplx | Complexity of the array to create. Valid values are mxREAL and mxCOMPLEX.
The default value is mxREAL. |
Create a 1-by-nmxCHAR_CLASS, with n = strlen(str),
and initialize the array's data with the characters in the supplied
string.
const char* str | Null-terminated character buffer used to initialize the array |
Create a matrix of type mxCHAR_CLASS, and
initialize the array's data with the characters in the supplied strings.
The created array has dimensions m-by-max, where max is the length
of the longest string in str.
mwSize num_strings | Number of strings in the input array |
const char** str | Array of null-terminated strings |
Create a matrix of type mxSTRUCT_CLASS, with
the specified field names. All elements are initialized with empty
cells.
mwSize num_rows | Number of rows in the array |
mwSize num_cols | Number of columns in the array |
int num_fields | Number of fields in the struct matrix. |
const char** fieldnames | Array of null-terminated strings representing the field names |
Create an n-dimensional array of type mxSTRUCT_CLASS,
with the specified field names. All elements are initialized with
empty cells.
mwSize num_dims | Number of dimensions in the array |
const | Dimensions of the array |
int num_fields | Number of fields in the struct matrix. |
const char** fieldnames | Array of null-terminated strings representing the field names |
Create a deep copy of an existing array.
mwArray& arr | mwArray to copy |
Create a real scalar array.
The scalar array is created with the type of the input argument.
<type> re | Scalar value to initialize the array. <type> can
be any of the following:
|
Create a complex scalar array.
The scalar array is created with the type of the input argument.
<type> re | Scalar value to initialize the real part of the array |
<type> im | Scalar value to initialize the imaginary part of the array |
<type> can be any of the following:
mxDouble
mxSingle
mxInt8
mxUint8
mxInt16
mxUint16
mxInt32
mxUint32
mxInt64
mxUint64
mxLogical
Create a new array representing deep copy of array.
mwArray a(2, 2, mxDOUBLE_CLASS); mwArray b = a.Clone();
Create a shared copy of an existing array. The new array and the original array both point to the same data.
mwArray a(2, 2, mxDOUBLE_CLASS); mwArray b = a.SharedCopy();
Serialize an array into bytes. A 1-by-n numeric
matrix of type mxUINT8_CLASS is returned containing
the serialized data. The data can be deserialized back into the original
representation by calling mwArray::Deserialize().
mwArray a(2, 2, mxDOUBLE_CLASS); mwArray b = a.Serialize();
Determine the type of the array. See the Work with mxArrays for
more information on mxClassID.
mwArray a(2, 2, mxDOUBLE_CLASS); mxClassID id = a.ClassID();
Determine the size, in bytes, of an element of array type.
mwArray a(2, 2, mxDOUBLE_CLASS); int size = a.ElementSize();
Determine the size, in bytes, of an element of array type.
mwArray a(2, 2, mxDOUBLE_CLASS); int size = a.ElementSize();
Determine the total size of the array.
mwArray a(2, 2, mxDOUBLE_CLASS); int n = a.NumberOfElements();
Determine the size of the of the array's data. If the underlying
array is not sparse, this returns the same value as NumberOfElements().
mwArray a(2, 2, mxDOUBLE_CLASS); int n = a.NumberOfNonZeros();
Determine the allocated size of the of the array's data. If
the underlying array is not sparse, this returns the same value as NumberOfElements().
mwArray a(2, 2, mxDOUBLE_CLASS); int n = a.MaximumNonZeros();
Determine the dimensionality of the array.
mwArray a(2, 2, mxDOUBLE_CLASS); int n = a.NumberOfDimensions();
Determine the number of fields in a struct array.
If the underlying array is not of type struct,
zero is returned.
const char* fields[] = {"a", "b", "c"};
mwArray a(2, 2, 3, fields);
int n = a.NumberOfFields();Determine the name of a given field in a struct array.
If the underlying array is not of type struct,
an exception is thrown.
int index | Index of the field to name. Indexing starts at zero. |
const char* fields[] = {"a", "b", "c"};
mwArray a(2, 2, 3, fields);
mwString tempname = a.GetFieldName(1);
const char* name = (const char*)tempname;Determine the size of each dimension in the array. The size
of the returned array is 1-by-NumberOfDimensions().
mwArray a(2, 2, mxDOUBLE_CLASS); mwArray dims = a.GetDimensions();
Determine if an array is empty.
mwArray a; bool b = a.IsEmpty();
Determine if an array is sparse.
mwArray a(2, 2, mxDOUBLE_CLASS); bool b = a.IsSparse();
Determine if an array is numeric.
mwArray a(2, 2, mxDOUBLE_CLASS); bool b = a.IsNumeric();
Determine if an array is complex.
mwArray a(2, 2, mxDOUBLE_CLASS, mxCOMPLEX); bool b = a.IsComplex();
Returns true if the input array is byte-wise
equal to this array. This method makes a byte-wise comparison of the
underlying arrays. Therefore, arrays of the same type should be compared.
Arrays of different types will not in general be equal, even if they
are initialized with the same data.
mwArray& arr | Array to compare to array. |
mwArray a(1, 1, mxDOUBLE_CLASS); mwArray b(1, 1, mxDOUBLE_CLASS); a = 1.0; b = 1.0; bool c = a.Equals(b);
Compares this array with the specified array for order. This method makes a byte-wise comparison of the underlying arrays. Therefore, arrays of the same type should be compared. Arrays of different types will, in general, not be ordered equivalently, even if they are initialized with the same data.
mwArray& arr | Array to compare to array. |
mwArray a(1, 1, mxDOUBLE_CLASS); mwArray b(1, 1, mxDOUBLE_CLASS); a = 1.0; b = 1.0; int n = a.CompareTo(b);
Constructs a unique hash value form the underlying bytes in the array. Therefore, arrays of different types will have different hash codes, even if they are initialized with the same data.
mwArray a(1, 1, mxDOUBLE_CLASS); int n = a.HashCode();
Returns a string representation of the underlying array. The string returned is the same string that is returned by typing a variable's name at the MATLAB command prompt.
mwArray a(1, 1, mxDOUBLE_CLASS, mxCOMPLEX);
a.Real() = 1.0;
a.Imag() = 2.0;
printf("%s\n", (const char*)(a.ToString()));Returns an array of type mxINT32_CLASS representing
the row indices (first dimension) of this array. For sparse arrays,
the indices are returned for just the non-zero elements and the size
of the array returned is 1-by-NumberOfNonZeros().
For nonsparse arrays, the size of the array returned is 1-by-NumberOfElements(),
and the row indices of all of the elements are returned.
#include <stdio.h> mwArray a(1, 1, mxDOUBLE_CLASS); mwArray rows = a.RowIndex();
Returns an array of type mxINT32_CLASS representing
the column indices (second dimension) of this array. For sparse arrays,
the indices are returned for just the non-zero elements and the size
of the array returned is 1-by-NumberOfNonZeros().
For nonsparse arrays, the size of the array returned is 1-by-NumberOfElements(),
and the column indices of all of the elements are returned.
mwArray a(1, 1, mxDOUBLE_CLASS); mwArray rows = a.ColumnIndex();
Convert a numeric array that has been previously allocated as real to complex.
If the underlying array is of a nonnumeric type, an mwException is
thrown.
double rdata[4] = {1.0, 2.0, 3.0, 4.0};
double idata[4] = {10.0, 20.0, 30.0, 40.0};
mwArray a(2, 2, mxDOUBLE_CLASS);
a.SetData(rdata, 4);
a.MakeComplex();
a.Imag().SetData(idata, 4);Fetches a single element at a specified index. The index is
passed by first passing the number of indices followed by a comma-separated
list of 1-based indices. The valid number of indices that can be passed
in is either 1 (single subscript indexing), in which case the element
at the specified 1-based offset is returned, accessing data in column-wise
order, or NumberOfDimensions() (multiple subscript
indexing), in which case, the index list is used to access the specified
element. The valid range for indices is 1 <= index <= NumberOfElements(),
for single subscript indexing. For multiple subscript indexing, the i1 <= index[i] <= GetDimensions().Get(1, i).
An mwException is thrown if an invalid number of
indices is passed in or if any index is out of bounds.
mwSize num_indices | Number of indices passed in |
... | Comma-separated list of input indices. Number of items must
equal num_indices but should not exceed 32. |
double data[4] = {1.0, 2.0, 3.0, 4.0};
double x;
mwArray a(2, 2, mxDOUBLE_CLASS);
a.SetData(data, 4);
x = a.Get(1,1);
x = a.Get(2, 1, 2);
x = a.Get(2, 2, 2);Fetches a single element at a specified field name and index.
This method may only be called on an array that is of type mxSTRUCT_CLASS.
An mwException is thrown if the underlying array
is not a struct array. The field name passed must
be a valid field name in the struct array. The
index is passed by first passing the number of indices followed by
a comma-separated list of 1-based indices. The valid number of indices
that can be passed in is either 1 (single subscript indexing), in
which case the element at the specified 1-based offset is returned,
accessing data in column-wise order, or NumberOfDimensions() (multiple
subscript indexing), in which case, the index list is used to access
the specified element. The valid range for indices is 1 <= index <= NumberOfElements(), for single subscript indexing.
For multiple subscript indexing, the ith index has the valid range: 1 <= index[i] <= GetDimensions().Get(1, i). An mwException is
thrown if an invalid number of indices is passed in or if any index
is out of bounds.
char* name | Null-terminated character buffer containing the name of the field |
mwSize num_indices | Number of indices passed in |
... | Comma-separated list of input indices. Number of items must
equal num_indices but should not exceed 32. |
const char* fields[] = {"a", "b", "c"};
mwArray a(1, 1, 3, fields);
mwArray b = a.Get("a", 1, 1);
mwArray b = a.Get("b", 2, 1, 1);Fetches a single element at a specified index. The index is
passed by first passing the number of indices, followed by an array
of 1-based indices. The valid number of indices that can be passed
in is either 1 (single subscript indexing), in which case the element
at the specified 1-based offset is returned, accessing data in column-wise
order, or NumberOfDimensions() (multiple subscript
indexing), in which case, the index list is used to access the specified
element. The valid range for indices is 1 <= index <= NumberOfElements(),
for single subscript indexing. For multiple subscript indexing, the
ith index has the valid range: 1 <= index[i] <= GetDimensions().Get(1,
i). An mwException is thrown if an invalid
number of indices is passed in or if any index is out of bounds.
mwSize num_indices | Size of index array |
| Array of at least size num_indices containing
the indices |
double data[4] = {1.0, 2.0, 3.0, 4.0};
int index[2] = {1, 1};
double x;
mwArray a(2, 2, mxDOUBLE_CLASS);
a.SetData(data, 4);
x = a.Get(1, index);
x = a.Get(2, index);
index[0] = 2;
index[1] = 2;
x = a.Get(2, index);Fetches a single element at a specified field name and index.
This method may only be called on an array that is of type mxSTRUCT_CLASS.
An mwException is thrown if the underlying array
is not a struct array. The field name passed must
be a valid field name in the struct array. The
index is passed by first passing the number of indices followed by
an array of 1-based indices. The valid number of indices that can
be passed in is either 1 (single subscript indexing), in which case
the element at the specified 1-based offset is returned, accessing
data in column-wise order, or NumberOfDimensions() (multiple
subscript indexing), in which case, the index list is used to access
the specified element. The valid range for indices is 1 <= index <= NumberOfElements(), for single subscript indexing.
For multiple subscript indexing, the ith index has the valid range: 1 <= index[i] <= GetDimensions().Get(1, i). An mwException is
thrown if an invalid number of indices is passed in or if any index
is out of bounds.
char* name | Null-terminated character buffer containing the name of the field |
mwSize num_indices | Number of indices passed in |
| Array of at least size num_indices containing
the indices |
const char* fields[] = {"a", "b", "c"};
int index[2] = {1, 1};
mwArray a(1, 1, 3, fields);
mwArray b = a.Get("a", 1, index);
mwArray b = a.Get("b", 2, index);Accesses the real part of a complex array. The returned mwArray is
considered real and has the same dimensionality and type as the original.
Complex arrays consist of Complex numbers, which are 1 X 2 vectors
(pairs). For example, if the number is 3+5i, then
the pair is (3,5i). An array of Complex numbers
is therefore two dimensional (N X 2), where N is
the number of complex numbers in the array. 2+4i, 7-3i, 8+6i would
be represented as (2,4i) (7,3i) (8,6i). Complex
numbers have two components, real and imaginary.
The MATLAB function Realcan be applied
to an array of Complex numbers. It extracts the corresponding part
of the Complex number. For example, REAL(3,5i) == 3.
double rdata[4] = {1.0, 2.0, 3.0, 4.0};
double idata[4] = {10.0, 20.0, 30.0, 40.0};
mwArray a(2, 2, mxDOUBLE_CLASS, mxCOMPLEX);
a.Real().SetData(rdata, 4);Accesses the imaginary part of a complex array. The returned mwArray is
considered real and has the same dimensionality and type as the original.
Complex arrays consist of Complex numbers, which are 1 X 2 vectors
(pairs). For example, if the number is 3+5i, then
the pair is (3,5i). An array of Complex numbers
is therefore two dimensional (N X 2), where N is
the number of complex numbers in the array. 2+4i, 7-3i, 8+6i would
be represented as (2,4i) (7,3i) (8,6i). Complex
numbers have two components, real and imaginary.
The MATLAB function Imag can be applied
to an array of Complex numbers. It extracts the corresponding part
of the Complex number. For example, IMAG(3+5i) == 5.
Imag returns 5 in this case
and not 5i. Imag returns the
magnitude of the imaginary part of the number as a real number.
double rdata[4] = {1.0, 2.0, 3.0, 4.0};
double idata[4] = {10.0, 20.0, 30.0, 40.0};
mwArray a(2, 2, mxDOUBLE_CLASS, mxCOMPLEX);
a.Imag().SetData(idata, 4);Assign shared copy of input array to currently referenced cell
for arrays of type mxCELL_CLASS and mxSTRUCT_CLASS.
| mwArray to assign to currently referenced
cell |
mwArray a(2, 2, mxDOUBLE_CLASS); mwArray b(2, 2, mxINT16_CLASS); mwArray c(1, 2, mxCELL_CLASS); c.Get(1,1).Set(a); c.Get(1,2).Set(b);
Copies the array's data into supplied numeric buffer.
The data is copied in column-major order. If the underlying
array is not of the same type as the input buffer, the data is converted
to this type as it is copied. If a conversion cannot be made, an mwException is
thrown.
| Buffer to receive copy. Valid types for <numeric-type> are:
|
| Maximum length of buffer. A maximum of len elements
will be copied. |
double rdata[4] = {1.0, 2.0, 3.0, 4.0};
double data_copy[4] ;
mwArray a(2, 2, mxDOUBLE_CLASS);
a.SetData(rdata, 4);
a.GetData(data_copy, 4);
Copies the array's data into supplied mxLogical buffer.
The data is copied in column-major order. If the underlying
array is not of type mxLOGICAL_CLASS, the data
is converted to this type as it is copied. If a conversion cannot
be made, an mwException is thrown.
| Buffer to receive copy |
| Maximum length of buffer. A maximum of len elements
will be copied. |
mxLogical data[4] = {true, false, true, false};
mxLogical data_copy[4] ;
mwArray a(2, 2, mxLOGICAL_CLASS);
a.SetLogicalData(data, 4);
a.GetLogicalData(data_copy, 4);Copies the array's data into supplied mxChar buffer.
The data is copied in column-major order. If the underlying
array is not of type mxCHAR_CLASS, the data is
converted to this type as it is copied. If a conversion cannot be
made, an mwException is thrown.
| Buffer to receive copy |
| Maximum length of buffer. A maximum of len elements
will be copied. |
mxChar data[6] = {'H', 'e' , `l' , 'l' , 'o' , '\0'};
mxChar data_copy[6] ;
mwArray a(1, 6, mxCHAR_CLASS);
a.SetCharData(data, 6);
a.GetCharData(data_copy, 6);Copies the data from supplied numeric buffer into the array.
The data is copied in column-major order. If the underlying
array is not of the same type as the input buffer, the data is converted
to this type as it is copied. If a conversion cannot be made, an mwException is
thrown.
| Buffer containing data to copy. Valid types for <numeric-type> are:
|
| Maximum length of buffer. A maximum of len elements
will be copied. |
double rdata[4] = {1.0, 2.0, 3.0, 4.0};
double data_copy[4] ;
mwArray a(2, 2, mxDOUBLE_CLASS);
a.SetData(rdata, 4);
a.GetData(data_copy, 4);
Copies the data from the supplied mxLogical buffer
into the array.
The data is copied in column-major order. If the underlying
array is not of type mxLOGICAL_CLASS, the data
is converted to this type as it is copied. If a conversion cannot
be made, an mwException is thrown.
| Buffer containing data to copy |
| Maximum length of buffer. A maximum of len elements
will be copied. |
mxLogical data[4] = {true, false, true, false};
mxLogical data_copy[4] ;
mwArray a(2, 2, mxLOGICAL_CLASS);
a.SetLogicalData(data, 4);
a.GetLogicalData(data_copy, 4);Copies the data from the supplied mxChar buffer
into the array.
The data is copied in column-major order. If the underlying
array is not of type mxCHAR_CLASS, the data is
converted to this type as it is copied. If a conversion cannot be
made, an mwException is thrown.
| Buffer containing data to copy |
| Maximum length of buffer. A maximum of len elements
will be copied. |
mxChar data[6] = {'H', 'e' , `l' , 'l' , 'o' , '\0'};
mxChar data_copy[6] ;
mwArray a(1, 6, mxCHAR_CLASS);
a.SetCharData(data, 6);
a.GetCharData(data_copy, 6);Deserializes an array that has been serialized with mwArray::Serialize().
The input array must be of type mxUINT8_CLASS and
contain the data from a serialized array. If the input data does not
represent a serialized mwArray, the behavior of
this method is undefined.
| mwArray that has been obtained by calling mwArray::Serialize |
double rdata[4] = {1.0, 2.0, 3.0, 4.0};
mwArray a(1,4,mxDOUBLE_CLASS);
a.SetData(rdata, 4);
mwArray b = a.Serialize();
a = mwArray::Deserialize(b);Creates real sparse matrix of type double with
specified number of rows and columns.
The lengths of input row, column index, and data arrays must all be the same or equal to 1. In the case where any of these arrays are equal to 1, the value is repeated throughout the construction of the matrix.
If any element of the rowindex or colindex array
is greater than the specified values in num_rows or num_cols respectively,
an exception is thrown.
| Size of rowindex array |
| Array of row indices of non-zero elements |
| Size of colindex array |
| Array of column indices of non-zero elements |
| Size of data array |
| Data associated with non-zero row and column indices |
| Number of rows in matrix |
| Number of columns in matrix |
| Reserved storage for sparse matrix. If nzmax is
zero, storage will be set to max{rowindex_size, colindex_size,
data_size}. |
This example constructs a sparse 4 X 4 tridiagonal matrix:
2 -1 0 0 -1 2 -1 0 0 -1 2 -1 0 0 -1 2
The following code, when run:
double rdata[] =
{2.0, -1.0, -1.0, 2.0, -1.0,
-1.0, 2.0, -1.0, -1.0, 2.0};
mwIndex row_tridiag[] =
{1, 2, 1, 2, 3,
2, 3, 4, 3, 4 };
mwIndex col_tridiag[] =
{1, 1, 2, 2, 2,
3, 3, 3, 4, 4 };
mwArray mysparse =
mwArray::NewSparse(10, row_tridiag,
10, col_tridiag,
10, rdata, 4, 4, 10);
std::cout << mysparse << std::endl;will display the following output to the screen:
(1,1) 2 (2,1) -1 (1,2) -1 (2,2) 2 (3,2) -1 (2,3) -1 (3,3) 2 (4,3) -1 (3,4) -1 (4,4) 2
Creates real sparse matrix of type double with
number of rows and columns inferred from input data.
The lengths of input row and column index and data arrays must all be the same or equal to 1. In the case where any of these arrays are equal to 1, the value is repeated through out the construction of the matrix.
The number of rows and columns in the created matrix are calculated
form the input rowindex and colindex arrays
as num_rows = max{rowindex}, num_cols = max{colindex}.
| Size of rowindex array |
| Array of row indices of non-zero elements |
| Size of colindex array |
| Array of column indices of non-zero elements |
| Size of data array |
| Data associated with non-zero row and column indices |
| Reserved storage for sparse matrix. If nzmax is
zero, storage will be set to max{rowindex_size, colindex_size,
data_size}. |
In this example, we construct a sparse 4 X 4 identity matrix. The value of 1.0 is copied to each non-zero element defined by row and column index arrays:
double one = 1.0;
mwIndex row_diag[] = {1, 2, 3, 4};
mwIndex col_diag[] = {1, 2, 3, 4};
mwArray mysparse =
mwArray::NewSparse(4, row_diag,
4, col_diag,
1, &one,
0);
std::cout << mysparse << std::endl;
(1,1) 1
(2,2) 1
(3,3) 1
(4,4) 1
Creates complex sparse matrix of type double with
specified number of rows and columns.
The lengths of input row and column index and data arrays must all be the same or equal to 1. In the case where any of these arrays are equal to 1, the value is repeated through out the construction of the matrix.
If any element of the rowindex or colindex array
is greater than the specified values in num_rows, num_cols,
respectively, then an exception is thrown.
| Size of rowindex array |
| Array of row indices of non-zero elements |
| Size of colindex array |
| Array of column indices of non-zero elements |
| Size of data array |
| Real part of data associated with non-zero row and column indices |
| Imaginary part of data associated with non-zero row and column indices |
| Number of rows in matrix |
| Number of columns in matrix |
| Reserved storage for sparse matrix. If nzmax is
zero, storage will be set to max{rowindex_size, colindex_size,
data_size}. |
This example constructs a complex tridiagonal matrix:
double rdata[] =
{2.0, -1.0, -1.0, 2.0, -1.0, -1.0, 2.0, -1.0, -1.0, 2.0};
double idata[] =
{20.0, -10.0, -10.0, 20.0, -10.0, -10.0, 20.0, -10.0,
-10.0, 20.0};
mwIndex row_tridiag[] =
{1, 2, 1, 2, 3, 2, 3, 4, 3, 4};
mwIndex col_tridiag[] =
{1, 1, 2, 2, 2, 3, 3, 3, 4, 4};
mwArray mysparse = mwArray::NewSparse(10, row_tridiag,
10, col_tridiag,
10, rdata,
idata, 4, 4, 10);
std::cout << mysparse << std::endl;
It displays the following output to the screen:
(1,1) 2.0000 +20.0000i (2,1) -1.0000 -10.0000i (1,2) -1.0000 -10.0000i (2,2) 2.0000 +20.0000i (3,2) -1.0000 -10.0000i (2,3) -1.0000 -10.0000i (3,3) 2.0000 +20.0000i (4,3) -1.0000 -10.0000i (3,4) -1.0000 -10.0000i (4,4) 2.0000 +20.0000i
Creates complex sparse matrix of type double with
number of rows and columns inferred from input data.
The lengths of input row and column index and data arrays must all be the same or equal to 1. In the case where any of these arrays are equal to 1, the value is repeated through out the construction of the matrix.
The number of rows and columns in the created matrix are calculated
form the input rowindex and colindex arrays
as num_rows = max{rowindex}, num_cols = max{colindex}.
| Size of rowindex array |
| Array of row indices of non-zero elements |
| Size of colindex array |
| Array of column indices of non-zero elements |
| Size of data array |
| Real part of data associated with non-zero row and column indices |
| Imaginary part of data associated with non-zero row and column indices |
| Reserved storage for sparse matrix. If nzmax is
zero, storage will be set to max{rowindex_size, colindex_size,
data_size}. |
This example constructs a complex matrix by inferring dimensions and storage allocation from the input data.
mwArray mysparse =
mwArray::NewSparse(10, row_tridiag,
10, col_tridiag,
10, rdata, idata,
0);
std::cout << mysparse << std::endl;
(1,1) 2.0000 +20.0000i
(2,1) -1.0000 -10.0000i
(1,2) -1.0000 -10.0000i
(2,2) 2.0000 +20.0000i
(3,2) -1.0000 -10.0000i
(2,3) -1.0000 -10.0000i
(3,3) 2.0000 +20.0000i
(4,3) -1.0000 -10.0000i
(3,4) -1.0000 -10.0000i
(4,4) 2.0000 +20.0000i
Creates logical sparse matrix with specified number of rows and columns.
The lengths of input row and column index and data arrays must all be the same or equal to 1. In the case where any of these arrays are equal to 1, the value is repeated throughout the construction of the matrix.
If any element of the rowindex or colindex array
is greater than the specified values in num_rows, num_cols,
respectively, then an exception is thrown.
| Size of rowindex array |
| Array of row indices of non-zero elements |
| Size of colindex array |
| Array of column indices of non-zero elements |
| Size of data array |
| Data associated with non-zero row and column indices |
| Number of rows in matrix |
| Number of columns in matrix |
| Reserved storage for sparse matrix. If nzmax is
zero, storage will be set to max{rowindex_size, colindex_size,
data_size}. |
This example creates a sparse logical 4 X 4 tridiagonal matrix,
assigning true to each non-zero value:
mxLogical one = true;
mwIndex row_tridiag[] =
{1, 2, 1, 2, 3,
2, 3, 4, 3, 4};
mwIndex col_tridiag[] =
{1, 1, 2, 2, 2,
3, 3, 3, 4, 4};
mwArray mysparse =
mwArray::NewSparse(10, row_tridiag,
10, col_tridiag,
1, &one,
4, 4, 10);
std::cout << mysparse << std::endl;
(1,1) 1
(2,1) 1
(1,2) 1
(2,2) 1
(3,2) 1
(2,3) 1
(3,3) 1
(4,3) 1
(3,4) 1
(4,4) 1
Creates logical sparse matrix with number of rows and columns inferred from input data.
The lengths of input row and column index and data arrays must all be the same or equal to 1. In the case where any of these arrays are equal to 1, the value is repeated through out the construction of the matrix.
The number of rows and columns in the created matrix are calculated
form the input rowindex and colindex arrays
as num_rows = max {rowindex}, num_cols = max {colindex}.
| Size of rowindex array |
| Array of row indices of non-zero elements |
| Size of colindex array |
| Array of column indices of non-zero elements |
| Size of data array |
| Data associated with non-zero row and column indices |
| Reserved storage for sparse matrix. If nzmax is
zero, storage will be set to max{rowindex_size, colindex_size,
data_size}. |
This example uses the data from the first example, but allows the number of rows, number of columns, and allocated storage to be calculated from the input data:
mwArray mysparse =
mwArray::NewSparse(10, row_tridiag,
10, col_tridiag,
1, &one,
0);
std::cout << mysparse << std::endl;
(1,1) 1
(2,1) 1
(1,2) 1
(2,2) 1
(3,2) 1
(2,3) 1
(3,3) 1
(4,3) 1
(3,4) 1
(4,4) 1Creates an empty sparse matrix. All elements in an empty sparse
matrix are initially zero, and the amount of allocated storage for
non-zero elements is specified by nzmax.
| Number of rows in matrix |
| Number of columns in matrix |
| Reserved storage for sparse matrix |
| Type of data to store in matrix. Currently, sparse matrices
of type double precision and logical are
supported. Pass mxDOUBLE_CLASS to create a double precision
sparse matrix. Pass mxLOGICAL_CLASS to create a logical sparse
matrix. |
| Complexity of matrix. Pass mxCOMPLEX to
create a complex sparse matrix and mxREAL to
create a real sparse matrix. This argument may
be omitted, in which case the default complexity is real |
This example constructs a real 3 X 3 empty sparse matrix of
type double with reserved storage for 4 non-zero
elements:
mwArray mysparse = mwArray::NewSparse
(3, 3, 4, mxDOUBLE_CLASS);
std::cout << mysparse << std::endl;
All zero sparse: 3-by-3
Get value of NaN (Not-a-Number).
Call mwArray::GetNaN to return the value
of NaN for your system. NaN is
the IEEE arithmetic representation for Not-a-Number. Certain mathematical
operations return NaN as a result, for example:
0.0/0.0
Inf-Inf
The value of NaN is built in to the system;
you cannot modify it.
double x = mwArray::GetNaN();
Returns the value of the MATLAB eps variable.
This variable is the distance from 1.0 to the next largest floating-point
number. Consequently, it is a measure of floating-point accuracy.
The MATLAB pinv and rank functions
use eps as a default tolerance.
double x = mwArray::GetEps();
Returns the value of the MATLAB internal Inf variable. Inf is
a permanent variable representing IEEE arithmetic positive infinity.
The value of Inf is built into the system; you
cannot modify it.
Operations that return Inf include
Division by 0. For example, 5/0 returns Inf.
Operations resulting in overflow. For example, exp(10000) returns Inf because
the result is too large to be represented on your machine.
double x = mwArray::GetInf();
Determine whether or not a value is finite. A number is finite
if it is greater than -Inf and less than Inf.
| Value to test for finiteness |
bool x = mwArray::IsFinite(1.0);
Determines whether or not a value is equal to infinity or minus
infinity. MATLAB stores the value of infinity in a permanent
variable named Inf, which represents IEEE arithmetic
positive infinity. The value of the variable, Inf,
is built into the system; you cannot modify it.
Operations that return infinity include
Division by 0. For example, 5/0 returns infinity.
Operations resulting in overflow. For example, exp(10000) returns
infinity because the result is too large to be represented on your
machine. If the value equals NaN (Not-a-Number),
then mxIsInf returns false.
In other words, NaN is not equal to infinity.
| Value to test for infiniteness |
bool x = mwArray::IsInf(1.0);
Determines whether or not the value is NaN. NaN is
the IEEE arithmetic representation for Not-a-Number. NaN is
obtained as a result of mathematically undefined operations such as
0.0/0.0
Inf-Inf
The system understands a family of bit patterns as representing NaN.
In other words, NaN is not a single value, rather
it is a family of numbers that the MATLAB software (and other
IEEE-compliant applications) use to represent an error condition or
missing data.
| Value to test for NaN |
bool x = mwArray::IsNaN(1.0);
Fetches a single element at a specified index. The index is
passed as a comma-separated list of 1-based indices. This operator
is overloaded to support 1 through 32 indices. The valid number of
indices that can be passed in is either 1 (single subscript indexing),
in which case the element at the specified 1-based offset is returned,
accessing data in column-wise order, or NumberOfDimensions() (multiple
subscript indexing), in which case, the index list is used to access
the specified element. The valid range for indices is 1 <= index <= NumberOfElements(), for single subscript indexing.
For multiple subscript indexing, the ith index has the valid range: 1 <= index[i] <= GetDimensions().Get(1, i). An mwException is
thrown if an invalid number of indices is passed in or if any index
is out of bounds.
| Comma-separated list of input indices |
double data[4] = {1.0, 2.0, 3.0, 4.0};
double x;
mwArray a(2, 2, mxDOUBLE_CLASS);
a.SetData(data, 4);
x = a(1,1);
x = a(1,2);
x = a(2,2);Fetches a single element at a specified field name and index.
This method may only be called on an array that is of type mxSTRUCT_CLASS.
An mwException is thrown if the underlying array
is not a struct array. The field name passed must
be a valid field name in the struct array. The
index is passed by first passing the number of indices, followed by
an array of 1-based indices. This operator is overloaded to support
1 through 32 indices. The valid number of indices that can be passed
in is either 1 (single subscript indexing), in which case the element
at the specified 1-based offset is returned, accessing data in column-wise
order, or NumberOfDimensions() (multiple subscript
indexing), in which case, the index list is used to access the specified
element. The valid range for indices is 1 <= index <= NumberOfElements(),
for single subscript indexing. For multiple subscript indexing, the
ith index has the valid range: 1 <= index[i] <= GetDimensions().Get(1,
i). An mwException is thrown if an invalid
number of indices is passed in or if any index is out of bounds.
| Null terminated string containing the field name to get |
| Comma-separated list of input indices |
const char* fields[] = {"a", "b", "c"};
int index[2] = {1, 1};
mwArray a(1, 1, 3, fields);
mwArray b = a("a", 1, 1);
mwArray b = a("b", 1, 1);Sets a single scalar value. This operator is overloaded for all numeric and logical types.
| Value to assign |
mwArray a(2, 2, mxDOUBLE_CLASS); a(1,1) = 1.0; a(1,2) = 2.0; a(2,1) = 3.0; a(2,2) = 4.0;
Fetches a single scalar value. This operator is overloaded for all numeric and logical types.
double data[4] = {1.0, 2.0, 3.0, 4.0};
double x;
mwArray a(2, 2, mxDOUBLE_CLASS);
a.SetData(data, 4);
x = (double)a(1,1);
x = (double)a(1,2);
x = (double)a(2,1);
x = (double)a(2,2);