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# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
# AMAP -- Vector linear transformation. Map the range of pixel values
# a1,a2 from a into the range b1,b2 in b. It is assumed that a1 < a2
# and b1 < b2.
procedure amapd (a, b, npix, a1, a2, b1, b2)
double a[ARB], b[ARB]
double a1, a2, b1, b2
double minout, maxout, aoff, boff, pixval
double scalar
int npix, i
begin
scalar = (double (b2) - double (b1)) / (double (a2) - double (a1))
minout = min (b1, b2)
maxout = max (b1, b2)
aoff = a1
boff = b1
do i = 1, npix {
pixval = (a[i] - aoff) * scalar
b[i] = max(minout, min(maxout, pixval + boff))
}
end
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