go-chart/seq/linear.go

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package seq
// Range returns the array values of a linear seq with a given start, end and optional step.
func Range(start, end float64) []float64 {
return Seq{NewLinear().WithStart(start).WithEnd(end).WithStep(1.0)}.Array()
}
// RangeWithStep returns the array values of a linear seq with a given start, end and optional step.
func RangeWithStep(start, end, step float64) []float64 {
return Seq{NewLinear().WithStart(start).WithEnd(end).WithStep(step)}.Array()
}
// NewLinear returns a new linear generator.
func NewLinear() *Linear {
return &Linear{step: 1.0}
}
// Linear is a stepwise generator.
type Linear struct {
start float64
end float64
step float64
}
// Start returns the start value.
func (lg Linear) Start() float64 {
return lg.start
}
// End returns the end value.
func (lg Linear) End() float64 {
return lg.end
}
// Step returns the step value.
func (lg Linear) Step() float64 {
return lg.step
}
// Len returns the number of elements in the seq.
func (lg Linear) Len() int {
if lg.start < lg.end {
return int((lg.end-lg.start)/lg.step) + 1
}
return int((lg.start-lg.end)/lg.step) + 1
}
// GetValue returns the value at a given index.
func (lg Linear) GetValue(index int) float64 {
fi := float64(index)
if lg.start < lg.end {
return lg.start + (fi * lg.step)
}
return lg.start - (fi * lg.step)
}
// WithStart sets the start and returns the linear generator.
func (lg *Linear) WithStart(start float64) *Linear {
lg.start = start
return lg
}
// WithEnd sets the end and returns the linear generator.
func (lg *Linear) WithEnd(end float64) *Linear {
lg.end = end
return lg
}
// WithStep sets the step and returns the linear generator.
func (lg *Linear) WithStep(step float64) *Linear {
lg.step = step
return lg
}