# How to change command: g:=(f,n) -> seq( subs(x=i, f) mod 12, i=1..n)?

How to change command:

g:=(f,n) -> seq( subs(x=i, f) mod 12, i=1..n)?

Maple says: Error, illegal use of an object as a name...

I try to create a melody generator that creates desired length of sequence of pitch numbers as output, when you have as input: function( function of x) and length of sequence.

for example: seq(modp(12, subs(x = i, x^2)), i = 1 .. n), but then Maple says: Error, unable to execute seq.

But for example with this: f := proc (g) options operator, arrow; round(g) end proc; a := seq(mod(f(i*log(i+1)), 12), i = 0 .. 30), you get( output):

g -> round(g)

0, 1, 2, 4, 6, 9, 0, 3, 6, 9, 0, 3, 7, 10, 2, 6, 9, 1, 5, 9, 1, 5, 9, 1, 5, 9, 2, 6, 10, 3, 7

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These work for me in Maple 16.01, pasted in as either 1D Maple Notation or as 2D Math input.

restart:

g:=(f,n) -> seq( eval(f, x=i) mod 12, i=1..n):

g(round(x*ln(x+1)),16);

1, 2, 4, 6, 9, 0, 3, 6, 9, 0, 3, 7, 10, 2, 6, 9

seq(modp(eval(round(x*ln(x+1)), x = i), 12), i = 1 .. 16);

1, 2, 4, 6, 9, 0, 3, 6, 9, 0, 3, 7, 10, 2, 6, 9

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How to change this: A := <g(round(x*ln(x+1)), 16)>; pointplot(A, style = point)?... It does plot points of sequence properly rather arbitrarily it seems. – alvoutila Dec 5 '12 at 10:15
Did you instead mean something like A := <g(round(x*ln(x+1)), 16)>; plots:-listplot(A, style = point); – acer Dec 6 '12 at 1:54
Or, if you insist on using pointplot, then something like A := <<seq(i,i=1..16)>|<g(round(x*ln(x+1)), 16)>>; plots:-pointplot(A, style = point); – acer Dec 6 '12 at 1:58
What does A := <<seq(i, i = 1 .. 16))>|<g(round(x*ln(x+1)), 16)>> mean – alvoutila Dec 7 '12 at 10:12
It assigns to A a 16-by-2 Matrix, whose first column consists of the integers from 1 to 16, and whose second column contains the result from calling g in that way. The Matrix is constructed from two 16-by-1 column Vectors. – acer Jan 30 '13 at 1:50