1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
|
package dstream
import "fmt"
type addcol struct {
xform
newname string
pos int
newdat []float64
first bool
}
// TODO make generic
// AddCol appends a new column of data to a Dstream. The new data is
// provided as a single array.
func AddCol(da Dstream, newdat []float64, newname string) Dstream {
r := &addcol{
xform: xform{
source: da,
},
newname: newname,
newdat: newdat,
}
for _, na := range r.source.Names() {
if newname == na {
msg := fmt.Sprintf("AddCol: a variable named '%s' already exists.", na)
panic(msg)
}
}
r.names = append(r.names, r.source.Names()...)
r.names = append(r.names, r.newname)
r.first = true
r.bdata = make([]interface{}, len(r.names))
return r
}
func (ac *addcol) Reset() {
ac.pos = 0
ac.first = true
ac.source.Reset()
}
func (ac *addcol) Next() bool {
if !ac.first {
ac.pos += ilen(ac.bdata[0])
}
ac.first = false
f := ac.source.Next()
if !f {
return false
}
for k := 0; k < ac.source.NumVar(); k++ {
ac.bdata[k] = ac.source.GetPos(k)
}
csize := ilen(ac.bdata[0])
ac.bdata[len(ac.bdata)-1] = ac.newdat[ac.pos : ac.pos+csize]
return true
}
|
