I want to compute the charateristic polynomials of some matrices (the number of matrices is more than 10000), and write the coefficients of the resulting polynomials to a text file. The entries of the given matrices are stored in a text file. More specifically, suppose that M_1, M_2 and M_3 are three matrices, and the entries of them are stored in a text file named "data.txt" in the following form:
1 2 3
4 5 6
7 8 9
1 -1 0
2 3 6
-3 0 2
2 1 -1
1 -1 -2
0 1 2
The resulting output file should be of the following format:
1, -15, 18, 0
1, -6, 13, -28
1, -3, 1, 3
I don't know how to repeatedly read the data from the given text file. I think the procedure should be as follows.
>fid_1:=Open("data_1.txt"): #data_1 is the output file
>ReadFile(fid); #since the number of matrices is very large, I want the data to be read once
>for i from 1 to numlines do
here I need repeatedly read the data to a matrix M (I don't know how to do);
writedata[APPEND]("data_1.txt",map(i-> coeff(p, x, i), [seq(i, i = 0 .. degree(p, x))])); #this statement cannot write the coefficients of a polynomial in the same row
Now as I'm pretty new to Maple, I don't know any better and can't seem to get any information out of the help documents.
Thanks a lot.