Function: totalfourier (f, x, p)
- Returns fourexpand (foursimp (fourier (f, x, p)), x, p, 'inf).
Function: opsubst (f, g, e)
- The function opsubst is similar to the function subst, except that opsubst only makes substitutions for the operators in an expression. In general, when f is an operator in the expression e, substitute g for f in the expression e.
- To determine the operator, opsubst sets inflag to true. This means opsubst substitutes for the internal, not the displayed, operator in the expression.
- To use this function write first load("opsubst").
(%i) load("fourie")$
(%i) f(x):=x;
(%i) totalfourier(f(x),x,1/2);
(%o) -('sum((-1)^n*sin(2*%pi*n*x)/n,n,1,inf))/%pi
(%i) FF:subst(3,inf,%);
(%o) -('sum((-1)^n*sin(2*%pi*n*x)/n,n,1,3))/%pi
(%i) load("opsubst")$
(%i) FG:opsubst(sum,'sum,FF);
(%o) -sum((-1)^n*sin(2*%pi*n*x)/n,n,1,3)/%pi
(%i) define(g(x),FG);
(%o) g(x):=-sum((-1)^n*sin(2*%pi*n*x)/n,n,1,3)/%pi
