numpy.matrix¶

class numpy.matrix

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, the string 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, or whether a view is constructed.

array

Examples

```>>> a = np.matrix('1 2; 3 4')
>>> print a
[[1 2]
[3 4]]
```
```>>> np.matrix([[1, 2], [3, 4]])
matrix([[1, 2],
[3, 4]])
```

Methods

 all([axis, out]) Test whether all matrix elements along a given axis evaluate to True. any([axis, out]) Test whether any array element along a given axis evaluates to True. argmax([axis, out]) Indices of the maximum values along an axis. argmin([axis, out]) Return the indices of the minimum values along an axis. argsort([axis, kind, order]) Returns the indices that would sort this array. astype(t) 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(a_min, a_max[, out]) Return an array whose values are limited to [a_min, a_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. 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([order]) Return a copy of the array collapsed into one dimension. getA() Return self as an ndarray object. getA1() Return self as a flattened ndarray. getH() Returns the (complex) conjugate transpose of self. getI() Returns the (multiplicative) inverse of invertible self. getT() 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 max([axis, out]) Return the maximum value along an axis. mean([axis, dtype, out]) Returns the average of the matrix elements along the given axis. min([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. prod([axis, dtype, out]) Return the product of the array elements over the given axis. ptp([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() Return a flattened array. 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, order]) Change shape and size of array in-place. round([decimals, out]) Return an array rounded a to the given number of decimals. searchsorted(v[, side]) 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, and UPDATEIFCOPY, respectively. sort([axis, kind, order]) Sort an array, in-place. squeeze() Remove single-dimensional entries from the shape of a. std([axis, dtype, out, ddof]) Return the standard deviation of the array elements along the given axis. sum([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. tofile(fid[, sep, format]) Write array to a file as text or binary (default). tolist() Return the matrix as a (possibly nested) list. tostring([order]) Construct a Python string 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([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.