I am trying to save the data in a CSV format. The current and desired outputs are attached.
import numpy as np
import csv
r = np.linspace(0, 100e-6, 5)
A=np.array([[23.9496871440374 - 1336167292.56833*r**2],
[21.986288555672 - 1373636804.80965*r**2]])
with open('Vel_Profiles.csv', 'w') as f:
writer = csv.writer(f)
writer.writerows((r,A))
The current output is
The desired output is
Here is what worked for me to get your expected output:
import numpy as np
import csv
r = np.linspace(0, 100e-6, 5)
A=np.array([[23.9496871440374 - 1336167292.56833*r**2],
[21.986288555672 - 1373636804.80965*r**2]])
out = np.vstack([r,A.squeeze()]).T
np.savetxt('Vel_Profiles.csv', out, delimiter=',', fmt=['%2.2E', '%.5f', '%.6f'])
output:
0.00E+00 23.94969 21.986289
2.50E-05 23.11458 21.127766
5.00E-05 20.60927 18.552197
7.50E-05 16.43375 14.259582
1.00E-04 10.58801 8.249921
UPDATE Specifying the format of all columns in a more general way like asked in the comments
r = np.linspace(0, 100e-6, 5)
A=np.array([[23.9496871440374 - 1336167292.56833*r**2],
[21.986288555672 - 1373636804.80965*r**2]])
out = np.vstack([r,A.squeeze()]).T
test = np.hstack([out,out,out])
print(test.shape)
# (5, 9)
# build list of same len than shape[1] with format
# here , we would have 3 times the same data next to each other so just multiply it by 3
my_format = ['%2.2E', '%.5f', '%.6f']
my_list_of_formats = my_format*3
# ['%2.2E', '%.5f', '%.6f', '%2.2E', '%.5f', '%.6f', '%2.2E', '%.5f', '%.6f']
#or like this:
my_list_of_formats = [my_format[i % 3] for i in range(test.shape[1])]
# ['%2.2E', '%.5f', '%.6f', '%2.2E', '%.5f', '%.6f', '%2.2E', '%.5f', '%.6f']
np.savetxt('Vel_Profiles.csv', test, delimiter=',', fmt=my_list_of_formats)
you can also specify just one format like '%2.2E' to fmt=, then every column gets formatted that way
fmt=['%2.2E', '%.5f', '%.6f', '%.6f', ...]). Is there a more efficient way to do it?
np.savetxt. If you only need one or two formats, just put it in a variable and make a list comprehension for example. I'll edit it in my answerYou don't need to use another library, you can use Numpy itself.
You can do this:
import numpy as np
np.savetxt('file_name.csv', your_array, delimiter=',')
If you need to stack your arrays first you can do something like this first:
array = np.vstack([r, A])
Check out the documentation here:
savetxt: https://numpy.org/doc/stable/reference/generated/numpy.savetxt.html
vstack: https://numpy.org/doc/stable/reference/generated/numpy.vstack.html
