Julia equivalent of Python (numpy.savetxt) and Matlab (save) commands?

Specific Domains Data
1

What is the Julia equivalent of the following Python and MATLAB codes?
I’m looking for identical formatting in the output.

After searching the documentation (e.g. JLD, CSV, DataFrames), I have not found a satisfactory answer, hence I’m asking here.

(MATLAB) Input:

p = [1 2]
q = [3 4]
save pqfile.txt p q -ascii -double

(MATLAB) Output:

1.0000000000000000e+00   2.0000000000000000e+00
3.0000000000000000e+00   4.0000000000000000e+00

(Python) Input:

import numpy as np
p = np.array([1, 2])
q = np.array([3, 4])
np.savetxt("pqfile.txt", [p, q], fmt='%.16e')

(Python) Output:

1.0000000000000000e+00   2.0000000000000000e+00
3.0000000000000000e+00   4.0000000000000000e+00
2

Would CSV work? Check out DelimitedFiles.

3

The easiest way is to use writedlm, but that won’t give you the exact same formatting:

using DelimitedFiles
p = [1, 2]
q = [3, 4]
writedlm("pqfile.txt", (p, q), "   ")

# Output:
# 1   2
# 3   4

If you want more control over the formatting you can write the file manually using the @printf macro and iterating over the arrays.

1 Like
4

Adding to the above questions, also check Formatting.jl if you are used to Python syntax.

5

I’m looking into Formatting.jl - does this package give only string output, or can it be used to write to files?

6

You can write any string to a file using
https://docs.julialang.org/en/v1/base/io-network/#Base.open