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+--- Thread: How to vstack matrixs in numpy with different numbers of columns (/thread-19183.html)
How to vstack matrixs in numpy with different numbers of columns - hlhp - Jun-17-2019
I want to stack matrixs together with different numbers of columns
The way I can think of is:
1.Find out how many columns in a
2.Add empty columns to b
3.Stack them together
Is there another way to make it simpler?
import numpy as np a = np.array([["A1", "B1", "C1"], ["A1", "B1", "C1"]]) b = np.array([["A2", "B2"], ["A2", "B2"]]) c = np.array([["A3", "B3"], ["A3", "B3"]]) print(np.vstack((a, b))) #This would not allowed, because a and b have different columns # The following Result is wanted # [['A2' 'B2' 'C2'] # ['A2' 'B2' 'C2'] # ['A3' 'B3' ''] # ['A3' 'B3' '']]
RE: How to vstack matrixs in numpy with different numbers of columns - scidam - Jun-17-2019
You cann't do this using numpy's
vstack, but desired behavior could be achieved using Pandas, e.g. import numpy as np
a = np.array([["A1", "B1", "C1"], ["A1", "B1", "C1"]])
b = np.array([["A2", "B2"], ["A2", "B2"]])
c = np.array([["A3", "B3"], ["A3", "B3"]])
a = pd.DataFrame(a, columns=None)
b = pd.DataFrame(b, columns=None)
pd.concat([a,b]).fillna('').values
RE: How to vstack matrixs in numpy with different numbers of columns - hlhp - Jun-17-2019
(Jun-17-2019, 05:20 AM)scidam Wrote: You cann't do this using numpy's vstack, but desired behavior could be achieved using Pandas, e.g.Thank you! works perfectly.