axis =0 || acxis =1
# encoding:utf-8
import numpy as np
a = np.array([1, 2, 3])
b = np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
b[1, 1] = 10
print a.shape
print b.shape
print a.dtype
print b
# encoding:utf-8
import numpy as np
persontype = np.dtype({
'names': ['name', 'age', 'chinese', 'math', 'english'],
'formats': ['S32', 'i', 'i', 'i', 'f']
})
peoples = np.array(
[
('zhangfei', 32, 75, 100, 90),
('guanyu', 24, 85, 96, 88.5),
('zhaoyun', 28, 85, 92, 96.5),
('huangzhong', 29, 65, 85, 100)
],
dtype=persontype
)
ages = peoples[:]['age']
chineses = peoples[:]['chinese']
math = peoples[:]['math']
english = peoples[:]['english']
print np.mean(ages)
print np.mean(chineses)
print np.mean(math)
print np.mean(english)
# encoding:utf-8
import numpy as np
a = np.array([
[1, 2, 3],
[4, 5, 6],
[7, 8, 9]
])
print np.amin(a)
print np.amin(a, 0)
print np.amin(a, 1)
print np.amax(a)
print np.amax(a, 0)
print np.amax(a, 1)
print np.ptp(a)
print np.ptp(a, 0)
print np.ptp(a, 1)
'''
最大值和最小值的差
8
[6 6 6]
[2 2 2]
'''
# 中位数
print u"中位数:"
print np.median(a)
print np.median(a, axis=0)
print np.median(a, axis=1)
'''
中位数:
5.0
[4. 5. 6.]
[2. 5. 8.]
'''
# 求平均数
print u"平均数:"
np.mean(a)
print np.mean(a, axis=0)
print np.mean(a, axis=1)
# 加权平均数
print u"加权平均数:"
b = np.array([1, 2, 3, 4])
wts = np.array([1, 2, 3, 4])
print np.average(b)
print np.average(b, weights=wts)
# 标准差
print u"标准差:"
c = np.array([1, 2, 3, 4])
print np.std(c)
# 方差
print u"方差:"
c = np.array([1, 2, 3, 4])
print np.var(c)
print u'排序'
d = np.array(
[
[4, 3, 2],
[2, 4, 1]
]
)
print np.sort(d)
print np.sort(d, axis=None)
print np.sort(d, axis=0)
print np.sort(d, axis=1)# encoding:utf-8
import numpy as np
x1 = np.arange(1, 11, 2) # 默认不包含最终值
x2 = np.linspace(1, 9, 5) # 默认包含最终值
print np.add(x1, x2) # 加法
print np.subtract(x1, x2) # 加法
print np.multiply(x1, x2) # 乘法
print np.divide(x1, x2) # 除法
print np.power(x1, x2) # 求N次方
print np.remainder(x1, x2) # 取余
# encoding:utf-8
import numpy as np
a = np.array([
[1, 2, 3],
[4, 5, 6],
[7, 8, 9]
])
print np.amin(a)
print np.amin(a, 0)
print np.amin(a, 1)
print np.amax(a)
print np.amax(a, 0)
print np.amax(a, 1)
print np.ptp(a)
print np.ptp(a, 0)
print np.ptp(a, 1)
'''
最大值和最小值的差
8
[6 6 6]
[2 2 2]
'''
# 中位数
print u"中位数:"
print np.median(a)
print np.median(a, axis=0)
print np.median(a, axis=1)
'''
中位数:
5.0
[4. 5. 6.]
[2. 5. 8.]
'''
# 求平均数
print u"平均数:"
np.mean(a)
print np.mean(a, axis=0)
print np.mean(a, axis=1)
# 加权平均数
print u"加权平均数:"
b = np.array([1, 2, 3, 4])
wts = np.array([1, 2, 3, 4])
print np.average(b)
print np.average(b, weights=wts)
# 标准差
print u"标准差:"
c = np.array([1, 2, 3, 4])
print np.std(c)
# 方差
print u"方差:"
c = np.array([1, 2, 3, 4])
print np.var(c)
print u'排序'
d = np.array(
[
[4, 3, 2],
[2, 4, 1]
]
)
print np.sort(d)
print np.sort(d, axis=None)
print np.sort(d, axis=0)
print np.sort(d, axis=1)
# encoding:utf-8
import numpy as np
a = np.array([
[1, 2, 3],
[4, 5, 6],
[7, 8, 9]
])
print np.amin(a)
print np.amin(a, 0)
print np.amin(a, 1)
print np.amax(a)
print np.amax(a, 0)
print np.amax(a, 1)
print np.ptp(a)
print np.ptp(a, 0)
print np.ptp(a, 1)
'''
最大值和最小值的差
8
[6 6 6]
[2 2 2]
'''
# 中位数
print u"中位数:"
print np.median(a)
print np.median(a, axis=0)
print np.median(a, axis=1)
'''
中位数:
5.0
[4. 5. 6.]
[2. 5. 8.]
'''
# 求平均数
print u"平均数:"
np.mean(a)
print np.mean(a, axis=0)
print np.mean(a, axis=1)
# 加权平均数
print u"加权平均数:"
b = np.array([1, 2, 3, 4])
wts = np.array([1, 2, 3, 4])
print np.average(b)
print np.average(b, weights=wts)
# 标准差
print u"标准差:"
c = np.array([1, 2, 3, 4])
print np.std(c)
# 方差
print u"方差:"
c = np.array([1, 2, 3, 4])
print np.var(c)
print u'排序'
d = np.array(
[
[4, 3, 2],
[2, 4, 1]
]
)
print np.sort(d)
print np.sort(d, axis=None)
print np.sort(d, axis=0)
print np.sort(d, axis=1)