def __getitem__(self, key):
# handle matrix builder syntax
if isinstance(key, str):
frame = sys._getframe().f_back
mymat = matrixlib.bmat(key, frame.f_globals, frame.f_locals)
return mymat
if not isinstance(key, tuple):
key = (key, )
# copy attributes, since they can be overridden in the first argument
trans1d = self.trans1d
ndmin = self.ndmin
matrix = self.matrix
axis = self.axis
objs = []
scalars = []
arraytypes = []
scalartypes = []
for k, item in enumerate(key):
scalar = False
if isinstance(item, slice):
step = item.step
start = item.start
stop = item.stop
if start is None:
start = 0
if step is None:
step = 1
if isinstance(step, complex):
size = int(abs(step))
newobj = linspace(start, stop, num=size)
else:
newobj = _nx.arange(start, stop, step)
if ndmin > 1:
newobj = array(newobj, copy=False, ndmin=ndmin)
if trans1d != -1:
newobj = newobj.swapaxes(-1, trans1d)
elif isinstance(item, str):
if k != 0:
raise ValueError("special directives must be the "
"first entry.")
if item in ('r', 'c'):
matrix = True
col = (item == 'c')
continue
if ',' in item:
vec = item.split(',')
try:
axis, ndmin = [int(x) for x in vec[:2]]
if len(vec) == 3:
trans1d = int(vec[2])
continue
except Exception as e:
raise ValueError(
"unknown special directive {!r}".format(
item)) from e
try:
axis = int(item)
continue
except (ValueError, TypeError):
raise ValueError("unknown special directive")
elif type(item) in ScalarType:
newobj = array(item, ndmin=ndmin)
scalars.append(len(objs))
scalar = True
scalartypes.append(newobj.dtype)
else:
item_ndim = ndim(item)
newobj = array(item, copy=False, subok=True, ndmin=ndmin)
if trans1d != -1 and item_ndim < ndmin:
k2 = ndmin - item_ndim
k1 = trans1d
if k1 < 0:
k1 += k2 + 1
defaxes = list(range(ndmin))
axes = defaxes[:k1] + defaxes[k2:] + defaxes[k1:k2]
newobj = newobj.transpose(axes)
objs.append(newobj)
if not scalar and isinstance(newobj, _nx.ndarray):
arraytypes.append(newobj.dtype)
# Ensure that scalars won't up-cast unless warranted
final_dtype = find_common_type(arraytypes, scalartypes)
if final_dtype is not None:
for k in scalars:
objs[k] = objs[k].astype(final_dtype)
res = self.concatenate(tuple(objs), axis=axis)
if matrix:
oldndim = res.ndim
res = self.makemat(res)
if oldndim == 1 and col:
res = res.T
return res
from matplotlib import pyplot as plt
from numpy.core import linspace
for tau in [0.1, 0.2, 0.25]:
y_arr = [2]
z_arr = [1]
t_end = 100
N_tau = int(t_end / tau)
for t in linspace(0, N_tau * tau, N_tau + 1):
f_i_j = -y_arr[-1] + 0.999 * z_arr[-1]
y_arr.append(y_arr[-1] + tau * (-(y_arr[-1] + tau/2*f_i_j) + 0.999 * (z_arr[-1] + tau/2)))
z_arr.append(z_arr[-1] + tau * (-0.001 * (z_arr[-1] + tau/2*f_i_j)))
plt.plot(y_arr, z_arr, label=f'tau: {tau}')
plt.legend()
plt.show()
#!/usr/bin/env python
# -*- coding: utf-8 -*-
import matplotlib.pyplot as plt
import math
import numpy.core as np
pisobre2 = math.pi / 2.0
#Defino funcion
def f1(x):
return 13.0 / (12.0 * math.pi) - (x**2) / math.pi**3
#Defino limites
x1 = np.linspace(-3.0, -pisobre2)
x2 = np.linspace(-pisobre2, pisobre2)
x3 = np.linspace(pisobre2, 3.0)
#Armo el gráfico
plt.plot(x1, [0.0 for x in x1], 'm', label='y = 2, x en [-oo, -pi/2]')
plt.plot(x2, [f1(i) for i in x2],
'm',
label='y = 13/(12*pi) - (x**2)/pi**3, x en [-pi/2, pi/2]')
plt.plot(x3, [0 for x in x3], 'm', label='y = 0, x en (pi/2, oo]')
plt.plot(-pisobre2,
0,
'mo',
markersize=5,
fillstyle='none',
markerfacecolor='w')
def __getitem__(self, key):
# handle matrix builder syntax
if isinstance(key, str):
frame = sys._getframe().f_back
mymat = matrixlib.bmat(key, frame.f_globals, frame.f_locals)
return mymat
if not isinstance(key, tuple):
key = (key,)
# copy attributes, since they can be overridden in the first argument
trans1d = self.trans1d
ndmin = self.ndmin
matrix = self.matrix
axis = self.axis
objs = []
scalars = []
arraytypes = []
scalartypes = []
for k, item in enumerate(key):
scalar = False
if isinstance(item, slice):
step = item.step
start = item.start
stop = item.stop
if start is None:
start = 0
if step is None:
step = 1
if isinstance(step, complex):
size = int(abs(step))
newobj = linspace(start, stop, num=size)
else:
newobj = _nx.arange(start, stop, step)
if ndmin > 1:
newobj = array(newobj, copy=False, ndmin=ndmin)
if trans1d != -1:
newobj = newobj.swapaxes(-1, trans1d)
elif isinstance(item, str):
if k != 0:
raise ValueError("special directives must be the "
"first entry.")
if item in ('r', 'c'):
matrix = True
col = (item == 'c')
continue
if ',' in item:
vec = item.split(',')
try:
axis, ndmin = [int(x) for x in vec[:2]]
if len(vec) == 3:
trans1d = int(vec[2])
continue
except Exception:
raise ValueError("unknown special directive")
try:
axis = int(item)
continue
except (ValueError, TypeError):
raise ValueError("unknown special directive")
elif type(item) in ScalarType:
newobj = array(item, ndmin=ndmin)
scalars.append(len(objs))
scalar = True
scalartypes.append(newobj.dtype)
else:
item_ndim = ndim(item)
newobj = array(item, copy=False, subok=True, ndmin=ndmin)
if trans1d != -1 and item_ndim < ndmin:
k2 = ndmin - item_ndim
k1 = trans1d
if k1 < 0:
k1 += k2 + 1
defaxes = list(range(ndmin))
axes = defaxes[:k1] + defaxes[k2:] + defaxes[k1:k2]
newobj = newobj.transpose(axes)
objs.append(newobj)
if not scalar and isinstance(newobj, _nx.ndarray):
arraytypes.append(newobj.dtype)
# Ensure that scalars won't up-cast unless warranted
final_dtype = find_common_type(arraytypes, scalartypes)
if final_dtype is not None:
for k in scalars:
objs[k] = objs[k].astype(final_dtype)
res = self.concatenate(tuple(objs), axis=axis)
if matrix:
oldndim = res.ndim
res = self.makemat(res)
if oldndim == 1 and col:
res = res.T
return res
print(arr)
print(arr.dtype)
'iplicit conversion'
arr1=array([1,5,7,8.0])
print(arr1.dtype)
'assigning type to array'
arr2=array([1,5,7,8.0],int)
print(arr2.dtype)
'linspace(it has 3 parameter 1.start 2.end_includeed 3.numberofparts and 3rd one is optional if it is not defined then it will divide in 50 equal parts) for array'
arr3 = linspace(0,15,16)
print(arr3)
'arange (it has 3 parameter 1.start 2.end_excluded 3.range and 3rd one is optional if it is not defined then range will be 1)'
arr4 = arange(0,15,3)
print(arr4)
'logspace'
arr5 = logspace(1,40,5)
print(arr5)
print('%.2f.'%arr5[4])
'Zeros'
arr6 = zeros(5)
arr7 = zeros(5,int)
