Helper API refactor (#40)

* api cleaup

* updates

* wtf

* updates

* snapshot.

* tweaks

* snapshot

* api tweaks.

* updates

* updates

* updates

* changes.

* updates

* updates

* sequence => seq

* dont need to use curl, just using wget

* fixing examples

util/math_test.go

@@ -0,0 +1,184 @@
+package util
+
+import (
+	"testing"
+	"time"
+
+	"github.com/blendlabs/go-assert"
+)
+
+func TestMinAndMax(t *testing.T) {
+	assert := assert.New(t)
+	values := []float64{1.0, 2.0, 3.0, 4.0}
+	min, max := Math.MinAndMax(values...)
+	assert.Equal(1.0, min)
+	assert.Equal(4.0, max)
+}
+
+func TestMinAndMaxReversed(t *testing.T) {
+	assert := assert.New(t)
+	values := []float64{4.0, 2.0, 3.0, 1.0}
+	min, max := Math.MinAndMax(values...)
+	assert.Equal(1.0, min)
+	assert.Equal(4.0, max)
+}
+
+func TestMinAndMaxEmpty(t *testing.T) {
+	assert := assert.New(t)
+	values := []float64{}
+	min, max := Math.MinAndMax(values...)
+	assert.Equal(0.0, min)
+	assert.Equal(0.0, max)
+}
+
+func TestMinAndMaxOfTime(t *testing.T) {
+	assert := assert.New(t)
+	values := []time.Time{
+		time.Now().AddDate(0, 0, -1),
+		time.Now().AddDate(0, 0, -2),
+		time.Now().AddDate(0, 0, -3),
+		time.Now().AddDate(0, 0, -4),
+	}
+	min, max := Math.MinAndMaxOfTime(values...)
+	assert.Equal(values[3], min)
+	assert.Equal(values[0], max)
+}
+
+func TestMinAndMaxOfTimeReversed(t *testing.T) {
+	assert := assert.New(t)
+	values := []time.Time{
+		time.Now().AddDate(0, 0, -4),
+		time.Now().AddDate(0, 0, -2),
+		time.Now().AddDate(0, 0, -3),
+		time.Now().AddDate(0, 0, -1),
+	}
+	min, max := Math.MinAndMaxOfTime(values...)
+	assert.Equal(values[0], min)
+	assert.Equal(values[3], max)
+}
+
+func TestMinAndMaxOfTimeEmpty(t *testing.T) {
+	assert := assert.New(t)
+	values := []time.Time{}
+	min, max := Math.MinAndMaxOfTime(values...)
+	assert.Equal(time.Time{}, min)
+	assert.Equal(time.Time{}, max)
+}
+
+func TestGetRoundToForDelta(t *testing.T) {
+	assert := assert.New(t)
+
+	assert.Equal(100.0, Math.GetRoundToForDelta(1001.00))
+	assert.Equal(10.0, Math.GetRoundToForDelta(101.00))
+	assert.Equal(1.0, Math.GetRoundToForDelta(11.00))
+}
+
+func TestRoundUp(t *testing.T) {
+	assert := assert.New(t)
+	assert.Equal(0.5, Math.RoundUp(0.49, 0.1))
+	assert.Equal(1.0, Math.RoundUp(0.51, 1.0))
+	assert.Equal(0.4999, Math.RoundUp(0.49988, 0.0001))
+}
+
+func TestRoundDown(t *testing.T) {
+	assert := assert.New(t)
+	assert.Equal(0.5, Math.RoundDown(0.51, 0.1))
+	assert.Equal(1.0, Math.RoundDown(1.01, 1.0))
+	assert.Equal(0.5001, Math.RoundDown(0.50011, 0.0001))
+}
+
+func TestPercentDifference(t *testing.T) {
+	assert := assert.New(t)
+
+	assert.Equal(0.5, Math.PercentDifference(1.0, 1.5))
+	assert.Equal(-0.5, Math.PercentDifference(2.0, 1.0))
+}
+
+func TestNormalize(t *testing.T) {
+	assert := assert.New(t)
+
+	values := []float64{10, 9, 8, 7, 6}
+	normalized := Math.Normalize(values...)
+	assert.Len(normalized, 5)
+	assert.Equal(0.25, normalized[0])
+	assert.Equal(0.1499, normalized[4])
+}
+
+var (
+	_degreesToRadians = map[float64]float64{
+		0:   0, // !_2pi b/c no irrational nums in floats.
+		45:  _pi4,
+		90:  _pi2,
+		135: _3pi4,
+		180: _pi,
+		225: _5pi4,
+		270: _3pi2,
+		315: _7pi4,
+	}
+
+	_compassToRadians = map[float64]float64{
+		0:   _pi2,
+		45:  _pi4,
+		90:  0, // !_2pi b/c no irrational nums in floats.
+		135: _7pi4,
+		180: _3pi2,
+		225: _5pi4,
+		270: _pi,
+		315: _3pi4,
+	}
+)
+
+func TestDegreesToRadians(t *testing.T) {
+	assert := assert.New(t)
+
+	for d, r := range _degreesToRadians {
+		assert.Equal(r, Math.DegreesToRadians(d))
+	}
+}
+
+func TestPercentToRadians(t *testing.T) {
+	assert := assert.New(t)
+
+	for d, r := range _degreesToRadians {
+		assert.Equal(r, Math.PercentToRadians(d/360.0))
+	}
+}
+
+func TestRadiansToDegrees(t *testing.T) {
+	assert := assert.New(t)
+
+	for d, r := range _degreesToRadians {
+		assert.Equal(d, Math.RadiansToDegrees(r))
+	}
+}
+
+func TestRadianAdd(t *testing.T) {
+	assert := assert.New(t)
+
+	assert.Equal(_pi, Math.RadianAdd(_pi2, _pi2))
+	assert.Equal(_3pi2, Math.RadianAdd(_pi2, _pi))
+	assert.Equal(_pi, Math.RadianAdd(_pi, _2pi))
+	assert.Equal(_pi, Math.RadianAdd(_pi, -_2pi))
+}
+
+func TestRotateCoordinate90(t *testing.T) {
+	assert := assert.New(t)
+
+	cx, cy := 10, 10
+	x, y := 5, 10
+
+	rx, ry := Math.RotateCoordinate(cx, cy, x, y, Math.DegreesToRadians(90))
+	assert.Equal(10, rx)
+	assert.Equal(5, ry)
+}
+
+func TestRotateCoordinate45(t *testing.T) {
+	assert := assert.New(t)
+
+	cx, cy := 10, 10
+	x, y := 5, 10
+
+	rx, ry := Math.RotateCoordinate(cx, cy, x, y, Math.DegreesToRadians(45))
+	assert.Equal(7, rx)
+	assert.Equal(7, ry)
+}