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1.创建数组
1.1 自动生成数组
name | describe |
---|---|
empty(shape[, dtype, order]) | Return a new array of given shape and type, without initializing entries. |
empty_like(a[, dtype, order, subok]) | Return a new array with the same shape and type as a given array. |
eye(N[, M, k, dtype]) | Return a 2-D array with ones on the diagonal and zeros elsewhere. |
identity(n[, dtype]) | Return the identity array. |
ones(shape[, dtype, order]) | Return a new array of given shape and type, filled with ones. |
ones_like(a[, dtype, order, subok]) | Return an array of ones with the same shape and type as a given array. |
zeros(shape[, dtype, order]) | Return a new array of given shape and type, filled with zeros. |
zeros_like(a[, dtype, order, subok]) | Return an array of zeros with the same shape and type as a given array. |
full(shape, fill_value[, dtype, order]) | Return a new array of given shape and type, filled with fill_value. |
full_like(a, fill_value[, dtype, order, subok]) | Return a full array with the same shape and type as a given array. |
arange([start,] stop[, step,][, dtype]) | Return evenly spaced values within a given interval. |
linspace(start, stop[, num, endpoint, …]) | Return evenly spaced numbers over a specified interval. |
logspace(start, stop[, num, endpoint, base, …]) | Return numbers spaced evenly on a log scale. |
geomspace(start, stop[, num, endpoint, dtype]) | Return numbers spaced evenly on a log scale (a geometric progression). |
meshgrid(*xi, **kwargs) | Return coordinate matrices from coordinate vectors. |
mgrid | nd_grid instance which returns a dense multi-dimensional “meshgrid”.) |
ogrid | nd_grid instance which returns an open multi-dimensional “meshgrid”.) |
1.2 从已有数据转化为数组
name | describe |
---|---|
array(object[, dtype, copy, order, subok, ndmin]) | Create an array. |
asarray(a[, dtype, order]) | Convert the input to an array. |
asanyarray(a[, dtype, order]) | Convert the input to an ndarray, but pass ndarray subclasses through. |
ascontiguousarray(a[, dtype]) | Return a contiguous array in memory (C order). |
asmatrix(data[, dtype]) | Interpret the input as a matrix. |
copy(a[, order]) | Return an array copy of the given object. |
frombuffer(buffer[, dtype, count, offset]) | Interpret a buffer as a 1-dimensional array. |
fromfile(file[, dtype, count, sep]) | Construct an array from data in a text or binary file. |
fromfunction(function, shape, **kwargs) | Construct an array by executing a function over each coordinate. |
fromiter(iterable, dtype[, count]) | Create a new 1-dimensional array from an iterable object. |
fromstring(string[, dtype, count, sep]) | A new 1-D array initialized from raw binary or text data in a string. |
loadtxt(fname[, dtype, comments, delimiter, …]) | Load data from a text file. |
2 数组属性与描述
name | describe |
---|---|
T | Same as self.transpose(), except that self is returned if self.ndim < 2. |
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. |
real | The real part of the array. |
size | Number of elements in 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. |
shape | Tuple of array dimensions. |
strides | Tuple of bytes to step in each dimension when traversing an array. |
ctypes | An object to simplify the interaction of the array with the ctypes module. |
base | Base object if memory is from some other object. |
3 数组方法与描述
name | describe |
---|---|
all([axis, out, keepdims]) | Returns True if all elements evaluate to True. |
any([axis, out, keepdims]) | Returns True if any of the elements of a evaluate to True. |
argmax([axis, out]) | Return indices of the maximum values along the given axis. |
argmin([axis, out]) | Return indices of the minimum values along the given axis of a. |
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([order]) | Return a copy of the array collapsed into one dimension. |
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([axis, out]) | Return the maximum along a given axis. |
mean([axis, dtype, out, keepdims]) | Returns the average of the array elements along given axis. |
min([axis, out, keepdims]) | Return the minimum along a given 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 value of the element in kth position prod([axis, dtype, out, keepdims]) Return the product of the array elements over the given axis |
ptp([axis, out]) | Peak to peak (maximum - minimum) value along a given axis. |
put(indices, values[, mode]) | Set a.flat[n] = values[n] for all n in indices. |
ravel([order]) | 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]) | 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, and UPDATEIFCOPY, respectively. |
sort([axis, kind, order]) | Sort an array, in-place. |
squeeze([axis]) | Remove single-dimensional entries from the shape of a. |
std([axis, dtype, out, ddof, keepdims]) | Returns the standard deviation of the array elements along given axis. |
sum([axis, dtype, out, keepdims]) | Return the sum of the array elements over 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() | Return the array 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([axis, dtype, out, ddof, keepdims]) | Returns the variance of the array elements, along given axis. |
view([dtype, type]) | New view of array with the same data. |
4 数组形态控制
name | describe |
---|---|
ndarray.reshape(shape[, order]) | Returns an array containing the same data with a new shape. |
ndarray.resize(new_shape[, refcheck]) | Change shape and size of array in-place. |
ndarray.transpose(*axes) | Returns a view of the array with axes transposed. |
ndarray.swapaxes(axis1, axis2) | Return a view of the array with axis1 and axis2 interchanged. |
ndarray.flatten([order]) | Return a copy of the array collapsed into one dimension. |
ndarray.ravel([order]) | Return a flattened array. |
ndarray.squeeze([axis]) | Remove single-dimensional entries from the shape of a. |
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