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1
4 package gnu.kawa.functions;
5 import gnu.lists.*;
6 import gnu.mapping.*;
7 import gnu.math.IntNum;
8
9
10
11 public class Arrays
12 {
13 static final int[] shapeStrides = { 2, 1} ;
14 static final int[] zeros2 = new int[2];
15
16 public static Array shape (Object  [] vals)
17 {
18 int len = vals.length;
19 if ((len & 1) != 0)
20 throw new RuntimeException ("shape: not an even number of arguments");
21 int d = len >> 1;
22 int[] dims = { d, 2 };
23 return new FVector(vals).transpose(zeros2, dims, 0, shapeStrides);
24 }
25
26 public static Array make(Array shape, Object value)
27 {
28 int rank = shape.getSize(0);
29 int[] dimensions = new int[rank];
30 int[] lowBounds = null;
31 int total = 1;
32 for (int i = rank; --i >= 0; )
33 {
34 int lo = ((Number ) shape.getRowMajor(2*i)).intValue();
35 int hi = ((Number ) shape.getRowMajor(2*i+1)).intValue();
36 int size = hi - lo;
37 dimensions[i] = size;
38 if (lo != 0)
39 {
40 if (lowBounds == null)
41 lowBounds = new int[rank];
42 lowBounds[i] = lo;
43 }
44 total *= size;
45 }
46 return GeneralArray.makeSimple(lowBounds, dimensions, new FVector(total, value));
47 }
48
49 public static Array makeSimple(Array shape, SimpleVector base)
50 {
51 int rank = shape.getSize(0);
52 int[] dimensions = new int[rank];
53 int[] lowBounds = null;
54 for (int i = rank; --i >= 0; )
55 {
56 int lo = ((Number ) shape.getRowMajor(2*i)).intValue();
57 int hi = ((Number ) shape.getRowMajor(2*i+1)).intValue();
58 dimensions[i] = hi - lo;
59 if (lo != 0)
60 {
61 if (lowBounds == null)
62 lowBounds = new int[rank];
63 lowBounds[i] = lo;
64 }
65 }
66 return GeneralArray.makeSimple(lowBounds, dimensions, base);
67 }
68
69 public static int effectiveIndex (Array array, Procedure proc,
70 Object [] args, int[] work)
71 throws Throwable
72 {
73 Object mapval = proc.applyN(args);
74 if (mapval instanceof Values)
75 {
76 Values mapvals = (Values) mapval;
77 for (int i = 0, j = 0; (i = mapvals.nextPos(i)) != 0; j++)
78 {
79 work[j] = ((Number ) mapvals.getPosPrevious(i)).intValue();
80 }
81 }
82 else
83 work[0] = ((Number ) mapval).intValue();
84 return array.getEffectiveIndex(work);
85 }
86
87 public static Array shareArray(Array array, Array shape,
88 Procedure proc)
89 throws Throwable
90 {
91 int rank = shape.getSize(0);
92 Object [] args = new Object [rank];
93 int[] dimensions = new int[rank];
94 int[] lowBounds = new int[rank]; boolean empty = false;
96 for (int i = rank; --i >= 0; )
97 {
98 Object low = shape.getRowMajor(2*i);
99 args[i] = low;
100 int lo = ((Number ) low).intValue();
101 lowBounds[i] = lo;
102 int hi = ((Number ) shape.getRowMajor(2*i+1)).intValue();
103 int size = hi - lo;
104 dimensions[i] = size;
105 if (size <= 0)
106 empty = true;
107 }
108 int arank = array.rank();
109 int[] offsets = new int[rank];
110 int offset0;
111 if (empty)
112 offset0 = 0;
113 else
114 {
115 int[] work = new int[arank];
116 offset0 = effectiveIndex (array, proc, args, work);
117 for (int i = rank; --i >= 0; )
118 {
119 int size = dimensions[i];
120 int lo = lowBounds[i];
121 if (size <= 1)
122 offsets[i] = 0;
123 else
124 {
125 Object low = args[i];
126 args[i] = IntNum.make(lo + 1);
127 offsets[i] = (effectiveIndex (array, proc, args, work)
128 - offset0);
129 args[i] = low;
130 }
131 }
132 }
133 return array.transpose(lowBounds, dimensions, offset0, offsets);
134 }
135 }
136 |
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