Compile question
- To: mathgroup at smc.vnet.net
- Subject: [mg73825] Compile question
- From: "Ray Koopman" <koopman at sfu.ca>
- Date: Thu, 1 Mar 2007 06:18:52 -0500 (EST)
I've been trying different ways to "walk the list" as suggested in
the recent thread "split again". Here is some uncompiled code that
works as I expected, but the compiled version returns reals instead
of integers. Does anyone know why?
SeedRandom[2]; z = Table[Random[],{20}]
{0.238705,0.844529,0.473928,0.421515,0.512692,
0.0228035,0.529257,0.0507012,0.74907,0.632356,
0.0725195,0.251276,0.902785,0.672727,0.419794,
0.512577,0.404555,0.00984124,0.168643,0.50482}
s4[z_,a_,b_] := Module[{n = Length@z, j = 0, k}, k = n;
Do[If[ z[[i]] >= a, If[ i <= j+b+1, j = i, k = i-1; Break[]]], {i,n}];
If[ k <= j+b, {}, {j+1,k} ] ]
s4[z,.7,5]
s4[z,.7,6]
s4[z,.7,7]
{3,8}
{14,20}
{}
s4c = Compile[{{z,_Real,1},{a,_Real},{b,_Integer}},
Module[{n = Length@z, j = 0, k}, k = n;
Do[If[ z[[i]] >= a, If[ i <= j+b+1, j = i, k = i-1; Break[]]], {i,n}];
If[ k <= j+b, {}, {j+1,k} ] ],
{{n,_Integer},{j,_Integer},{k,_Integer},{i,_Integer}} ];
s4c[z,.7,5]
s4c[z,.7,6]
s4c[z,.7,7}
{3.,8.}
{14.,20.}
{}