func scale(f *data.Slice, factor float32) {
a := f.Vectors()
for i := range a[0] {
for j := range a[0][i] {
for k := range a[0][i][j] {
a[0][i][j][k] *= factor
a[1][i][j][k] *= factor
a[2][i][j][k] *= factor
}
}
}
}
func normpeak(f *data.Slice) {
a := f.Vectors()
maxnorm := 0.
for i := range a[0] {
for j := range a[0][i] {
for k := range a[0][i][j] {
x, y, z := a[0][i][j][k], a[1][i][j][k], a[2][i][j][k]
norm := math.Sqrt(float64(x*x + y*y + z*z))
if norm > maxnorm {
maxnorm = norm
}
}
}
}
scale(f, float32(1/maxnorm))
}
// normalize vector data to given length
func normalize(f *data.Slice, length float64) {
a := f.Vectors()
for i := range a[0] {
for j := range a[0][i] {
for k := range a[0][i][j] {
x, y, z := a[0][i][j][k], a[1][i][j][k], a[2][i][j][k]
norm := math.Sqrt(float64(x*x + y*y + z*z))
invnorm := float32(1)
if norm != 0 {
invnorm = float32(length / norm)
}
a[0][i][j][k] *= invnorm
a[1][i][j][k] *= invnorm
a[2][i][j][k] *= invnorm
}
}
}
}
func Image(f *data.Slice, fmin, fmax string) *image.NRGBA {
dim := f.NComp()
switch dim {
default:
log.Fatalf("unsupported number of components: %v", dim)
case 3:
return drawVectors(f.Vectors())
case 1:
min, max := extrema(f.Host()[0])
if fmin != "auto" {
m, err := strconv.ParseFloat(fmin, 32)
util.FatalErr(err)
min = float32(m)
}
if fmax != "auto" {
m, err := strconv.ParseFloat(fmax, 32)
util.FatalErr(err)
max = float32(m)
}
return drawFloats(f.Scalars(), min, max)
}
panic("unreachable")
}
