func identityMat4() [16]float {
return {
1, 0, 0, 0,
0, 1, 0, 0,
0, 0, 1, 0,
0, 0, 0, 1 }
}
I hope you get the idea of what I'm trying to do from the example. How do I do this in Go?
-
Why is your matrix a one-dimensional array? Go supports multi-dimensional arrays / slices - wouldn't these be a better fit for the problem? (golang.org/ref/spec#Array_types)Rick-777– Rick-7772012-12-09 15:05:53 +00:00Commented Dec 9, 2012 at 15:05
Add a comment
|
3 Answers
func identityMat4() [16]float64 {
return [...]float64{
1, 0, 0, 0,
0, 1, 0, 0,
0, 0, 1, 0,
0, 0, 0, 1 }
}
3 Comments
peterSO
You are not returning an identity matrix.
Ivan Aracki
also you can write return [16]float64
SwiftMango
Upvoted for use of "three dots". Never knew that! Go lang is a simple language but so much small details to learn!
How to use an array initializer to initialize a test table block:
tables := []struct {
input []string
result string
} {
{[]string{"one ", " two", " three "}, "onetwothree"},
{[]string{" three", "four ", " five "}, "threefourfive"},
}
for _, table := range tables {
result := StrTrimConcat(table.input...)
if result != table.result {
t.Errorf("Result was incorrect. Expected: %v. Got: %v. Input: %v.", table.result, result, table.input)
}
}
Comments
If you were writing your program using Go idioms, you would be using slices. For example,
package main
import "fmt"
func Identity(n int) []float {
m := make([]float, n*n)
for i := 0; i < n; i++ {
for j := 0; j < n; j++ {
if i == j {
m[i*n+j] = 1.0
}
}
}
return m
}
func main() {
fmt.Println(Identity(4))
}
Output: [1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1]
2 Comments
Jeff Allen
See blog.golang.org/2011/01/go-slices-usage-and-internals.html for the difference between arrays and slices.
tbone
The official Go blog now specifically points out transformation matrices as one of the few good use cases for using arrays directly: "Arrays have their place — they are a good representation of a transformation matrix for instance — but their most common purpose in Go is to hold storage for a slice."