# numpy.matrix¶

class `numpy.``matrix`(data, dtype=None, copy=True)[source]

Note

It is no longer recommended to use this class, even for linear algebra. Instead use regular arrays. The class may be removed in the future.

Returns a matrix from an array-like object, or from a string of data. A matrix is a specialized 2-D array that retains its 2-D nature through operations. It has certain special operators, such as `*` (matrix multiplication) and `**` (matrix power).

Parameters: data : array_like or string If `data` is a string, it is interpreted as a matrix with commas or spaces separating columns, and semicolons separating rows. dtype : data-type Data-type of the output matrix. copy : bool If `data` is already an `ndarray`, then this flag determines whether the data is copied (the default), or whether a view is constructed.

Examples

```>>> a = np.matrix('1 2; 3 4')
>>> a
matrix([[1, 2],
[3, 4]])
```
```>>> np.matrix([[1, 2], [3, 4]])
matrix([[1, 2],
[3, 4]])
```
Attributes: `A` Return self as an `ndarray` object. `A1` Return self as a flattened `ndarray`. `H` Returns the (complex) conjugate transpose of self. `I` Returns the (multiplicative) inverse of invertible self. `T` Returns the transpose of the matrix. `base` Base object if memory is from some other object. `ctypes` An object to simplify the interaction of the array with the ctypes module. `data` Python buffer object pointing to the start of the array’s data. `dtype` Data-type of the array’s elements. `flags` Information about the memory layout of the array. `flat` A 1-D iterator over the array. `imag` The imaginary part of the array. `itemsize` Length of one array element in bytes. `nbytes` Total bytes consumed by the elements of the array. `ndim` Number of array dimensions. `real` The real part of the array. `shape` Tuple of array dimensions. `size` Number of elements in the array. `strides` Tuple of bytes to step in each dimension when traversing an array.

Methods

 `all`(self[, axis, out]) Test whether all matrix elements along a given axis evaluate to True. `any`(self[, axis, out]) Test whether any array element along a given axis evaluates to True. `argmax`(self[, axis, out]) Indexes of the maximum values along an axis. `argmin`(self[, axis, out]) Indexes of the minimum values along an axis. `argpartition`(kth[, axis, kind, order]) Returns the indices that would partition this array. `argsort`([axis, kind, order]) Returns the indices that would sort this array. `astype`(dtype[, order, casting, subok, copy]) Copy of the array, cast to a specified type. `byteswap`([inplace]) Swap the bytes of the array elements `choose`(choices[, out, mode]) Use an index array to construct a new array from a set of choices. `clip`([min, max, out]) Return an array whose values are limited to `[min, max]`. `compress`(condition[, axis, out]) Return selected slices of this array along given axis. `conj`() Complex-conjugate all elements. `conjugate`() Return the complex conjugate, element-wise. `copy`([order]) Return a copy of the array. `cumprod`([axis, dtype, out]) Return the cumulative product of the elements along the given axis. `cumsum`([axis, dtype, out]) Return the cumulative sum of the elements along the given axis. `diagonal`([offset, axis1, axis2]) Return specified diagonals. `dot`(b[, out]) Dot product of two arrays. `dump`(file) Dump a pickle of the array to the specified file. `dumps`() Returns the pickle of the array as a string. `fill`(value) Fill the array with a scalar value. `flatten`(self[, order]) Return a flattened copy of the matrix. `getA`(self) Return self as an `ndarray` object. `getA1`(self) Return self as a flattened `ndarray`. `getH`(self) Returns the (complex) conjugate transpose of self. `getI`(self) Returns the (multiplicative) inverse of invertible self. `getT`(self) Returns the transpose of the matrix. `getfield`(dtype[, offset]) Returns a field of the given array as a certain type. `item`(*args) Copy an element of an array to a standard Python scalar and return it. `itemset`(*args) Insert scalar into an array (scalar is cast to array’s dtype, if possible) `max`(self[, axis, out]) Return the maximum value along an axis. `mean`(self[, axis, dtype, out]) Returns the average of the matrix elements along the given axis. `min`(self[, axis, out]) Return the minimum value along an axis. `newbyteorder`([new_order]) Return the array with the same data viewed with a different byte order. `nonzero`() Return the indices of the elements that are non-zero. `partition`(kth[, axis, kind, order]) Rearranges the elements in the array in such a way that the value of the element in kth position is in the position it would be in a sorted array. `prod`(self[, axis, dtype, out]) Return the product of the array elements over the given axis. `ptp`(self[, axis, out]) Peak-to-peak (maximum - minimum) value along the given axis. `put`(indices, values[, mode]) Set `a.flat[n] = values[n]` for all n in indices. `ravel`(self[, order]) Return a flattened matrix. `repeat`(repeats[, axis]) Repeat elements of an array. `reshape`(shape[, order]) Returns an array containing the same data with a new shape. `resize`(new_shape[, refcheck]) Change shape and size of array in-place. `round`([decimals, out]) Return a with each element rounded to the given number of decimals. `searchsorted`(v[, side, sorter]) Find indices where elements of v should be inserted in a to maintain order. `setfield`(val, dtype[, offset]) Put a value into a specified place in a field defined by a data-type. `setflags`([write, align, uic]) Set array flags WRITEABLE, ALIGNED, (WRITEBACKIFCOPY and UPDATEIFCOPY), respectively. `sort`([axis, kind, order]) Sort an array in-place. `squeeze`(self[, axis]) Return a possibly reshaped matrix. `std`(self[, axis, dtype, out, ddof]) Return the standard deviation of the array elements along the given axis. `sum`(self[, axis, dtype, out]) Returns the sum of the matrix elements, along the given axis. `swapaxes`(axis1, axis2) Return a view of the array with axis1 and axis2 interchanged. `take`(indices[, axis, out, mode]) Return an array formed from the elements of a at the given indices. `tobytes`([order]) Construct Python bytes containing the raw data bytes in the array. `tofile`(fid[, sep, format]) Write array to a file as text or binary (default). `tolist`(self) Return the matrix as a (possibly nested) list. `tostring`([order]) Construct Python bytes containing the raw data bytes in the array. `trace`([offset, axis1, axis2, dtype, out]) Return the sum along diagonals of the array. `transpose`(*axes) Returns a view of the array with axes transposed. `var`(self[, axis, dtype, out, ddof]) Returns the variance of the matrix elements, along the given axis. `view`([dtype, type]) New view of array with the same data.

numpy.matrix.A

numpy.matrix.all