# saving polynomials and matrices in files

Use the function toString to convert polynomials, matrices, and other mathematical objects to a linear format that can be saved in a file.
 ```i1 : R = QQ[x..z] o1 = R o1 : PolynomialRing``` ```i2 : p = (x-y-1)^3 3 2 2 3 2 2 o2 = x - 3x y + 3x*y - y - 3x + 6x*y - 3y + 3x - 3y - 1 o2 : R``` ```i3 : m = matrix {{x^2, x^2-y^2, x*y*z^7 }} o3 = | x2 x2-y2 xyz7 | 1 3 o3 : Matrix R <--- R``` ```i4 : M = image m o4 = image | x2 x2-y2 xyz7 | 1 o4 : R-module, submodule of R``` ```i5 : f = temporaryFileName() o5 = /tmp/M2-10872-1``` ```i6 : f << toString (p,m,M) << close o6 = /tmp/M2-10872-1 o6 : File``` ```i7 : get f o7 = (x^3-3*x^2*y+3*x*y^2-y^3-3*x^2+6*x*y-3*y^2+3*x-3*y-1,matrix {{x^2, x^2-y^2, x*y*z^7}},image matrix {{x^2, x^2-y^2, x*y*z^7}})``` ```i8 : (p',m',M') = value get f 3 2 2 3 2 2 o8 = (x - 3x y + 3x*y - y - 3x + 6x*y - 3y + 3x - 3y - 1, | x2 x2-y2 ------------------------------------------------------------------------ xyz7 |, image | x2 x2-y2 xyz7 |) o8 : Sequence``` ```i9 : p == p' o9 = true``` ```i10 : m == m' o10 = true``` ```i11 : M == M' o11 = true``` `i12 : removeFile f`