Singular

Thank you. It works now. To avoid defining the list every time I read the file, I added a declaration before your for loop:

write(fil, "list " + nam + ";");

Thanks again.

Ravi :)

The cast matrix is incomplete, dimensions nrows and ncols are missing.

To fix the problem for the datataypes matrix and intmat,
change the for-loop as follows

[code]
for( i=1;i<=size(L);i=i+1 )
{
if (typeof(L[i]) == "intmat")
{
write(fil," "+nam+"["+string(i)+"]="+
"intmat(intvec("+string(L[i])+
"),"+string(nrows(L[i]))+","+string(ncols(L[i]))+");");
}
if ( typeof(L[i])== "matrix")
{
write(fil," "+nam+"["+string(i)+"]="+
"matrix(ideal("+string(L[i])+
"),"+string(nrows(L[i]))+","+string(ncols(L[i]))+");");
}
else
{
write(fil," "+nam+"["+string(i)+"]="+typeof(L[i])+"(",string(L[i])+");");
}
}
[/code]

(Note: Other datatypes as [i]string [/i] also do not work properly.)

I have a problem using the writelist function when I write a list of matrices to a file and want to recreate the list in memory by reading the file later on. Here is a simple example:

[code]
ring R = 0, (x,y,z), dp;
matrix A[3][3] = 0,1,0, -1,0,0, 0,0,1;
matrix B[3][3] = 0,1,0, 0,0,1, 1,0,0;
matrix C[3][3] = 0,1,0, 1,0,0, 0,0,1;
list L = A,B,C;
writelist("simple-write.txt", "simplist", L);
[/code]

This creates the text file alright:
list simplist;
simplist[1]=matrix(
0,1,0,-1,0,0,0,0,1);
etc...

but when I try to read it and recreate simplist:

[code]
ring R = 0, (x,y,z), dp;
execute(read("simple-write.txt")); // does not create the list simplist in memory
[/code]

The error I get is:
[code]
? error occurred in Read-Oh.sing line 10: `0,1,0,-1,0,0,0,0,1);`
? wrong type declaration. type 'help matrix;'
? last reserved name was `matrix`
skipping text from `-` error at token `)`
[/code]
According to the help files (D.2.4.9), this should create the object simplist. It works for other objects, but not for lists of matrices.
If someone can tell me what is going wrong, I shall be most grateful...

Ravi