Download or view intervaltest.frink in plain text format
// This is an external test to validate Frink's internal interval arithmetic.
// Ordinarily, multiplication of intervals make take 8 multiplications (or 16,
// if you're doing it rigorously.) You can break this down into 9 different
// cases and perform 8 of those with 2 multiplications, and 4 for the remaining
// case. Of course, the probability of introducing error in any of those
// cases increases. This program tests the naive method against Frink's
// internal methods.
for xl = -5 to 5 step 1/2
for xh = xl to 6 step 1/2
for yl = -5 to 5 step 1/2
for yh = yl to 6 step 1/2
{
naiveMultiply[[xl,xh],[yl,yh]]
naivePower[[xl,xh],[yl,yh]]
}
// Multiply two arrays naively.
naiveMultiply[x,y] :=
{
[xl, xh] = x
[yl, yh] = y
array = [xl*yl, xl*yh, xh*yl, xh*yh]
lo = min[array]
hi = max[array]
if lo==hi
println[lo]
else
println[[lo,hi]]
println[new interval[xl, xh] * new interval[yl, yh]]
}
// Exponentiate two arrays naively.
naivePower[x,y] :=
{
[xl, xh] = x
if ((xl>0) and (xh > 0))
{
[yl, yh] = y
array = [xl^yl, xl^yh, xh^yl, xh^yh]
lo = min[array]
hi = max[array]
if lo==hi
println["$x^$y $lo"]
else
println["$x^$y [$lo, $hi]"]
println["$x^$y " + new interval[xl, xh] ^ new interval[yl, yh]]
}
}
Download or view intervaltest.frink in plain text format
This is a program written in the programming language Frink.
For more information, view the Frink
Documentation or see More Sample Frink Programs.
Alan Eliasen was born 19966 days, 18 hours, 54 minutes ago.