Multiple regression: Difference between revisions
Go solution
m (→{{header|Ada}}: fix bug from Reduced row echolon form procedure) |
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-1.51161E+02
6.43514E+01</pre>
=={{header|Go}}==
The [http://en.wikipedia.org/wiki/Ordinary_least_squares#Example_with_real_data example] on WP happens to be a polynomial regression example, and so code from the [http://rosettacode.org/wiki/Polynomial_Fitting Polynomial regression] task can be reused here. The only difference here is that givens x and y are computed in a separate function as a task prerequisite.
<lang go>package main
import (
"fmt"
"gomatrix.googlecode.com/hg/matrix"
)
func givens() (x, y *matrix.DenseMatrix) {
height := []float64{1.47, 1.50, 1.52, 1.55, 1.57, 1.60, 1.63,
1.65, 1.68, 1.70, 1.73, 1.75, 1.78, 1.80, 1.83}
weight := []float64{52.21, 53.12, 54.48, 55.84, 57.20, 58.57, 59.93,
61.29, 63.11, 64.47, 66.28, 68.10, 69.92, 72.19, 74.46}
m := len(height)
n := 3
y = matrix.MakeDenseMatrix(weight, m, 1)
x = matrix.Zeros(m, n)
for i := 0; i < m; i++ {
ip := float64(1)
for j := 0; j < n; j++ {
x.Set(i, j, ip)
ip *= height[i]
}
}
return
}
func main() {
x, y := givens()
n := x.Cols()
q, r := x.QR()
qty, err := q.Transpose().Times(y)
if err != nil {
fmt.Println(err)
return
}
c := make([]float64, n)
for i := n - 1; i >= 0; i-- {
c[i] = qty.Get(i, 0)
for j := i + 1; j < n; j++ {
c[i] -= c[j] * r.Get(i, j)
}
c[i] /= r.Get(i, i)
}
fmt.Println(c)
}</lang>
Output:
<pre>
[128.8128035784373 -143.16202286476116 61.960325442472865]
</pre>
=={{header|Haskell}}==
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