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• Functions and Variables for opsubst: |
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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.
Examples:
(%i1) load ("opsubst")$ (%i2) opsubst(f,g,g(g(x))); (%o2) f(f(x)) (%i3) opsubst(f,g,g(g)); (%o3) f(g) (%i4) opsubst(f,g[x],g[x](z)); (%o4) f(z) (%i5) opsubst(g[x],f, f(z)); (%o5) g (z) x (%i6) opsubst(tan, sin, sin(sin)); (%o6) tan(sin) (%i7) opsubst([f=g,g=h],f(x)); (%o7) h(x)
Internally, Maxima does not use the unary negation, division, or the subtraction operators; thus:
(%i8) opsubst("+","-",a-b); (%o8) a - b (%i9) opsubst("f","-",-a); (%o9) - a (%i10) opsubst("^^","/",a/b); a (%o10) - b
The internal representation of -a*b is *(-1,a,b); thus
(%i11) opsubst("[","*", -a*b); (%o11) [- 1, a, b]
When either operator isn’t a Maxima symbol, generally some other function will signal an error:
(%i12) opsubst(a+b,f, f(x)); Improper name or value in functional position: b + a -- an error. Quitting. To debug this try debugmode(true);
However, subscripted operators are allowed:
(%i13) opsubst(g[5],f, f(x)); (%o13) g (x) 5
To use this function write first load("opsubst")
.
Categories: Expressions Share packages Package opsubst
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