aboutsummaryrefslogtreecommitdiff
path: root/math/curfit/cv_fevalr.x
blob: ac0190422d27755f32273820c6351875c34eb4b0 (plain) (blame)
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
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.

# CV_EVCHEB -- Procedure to evaluate a Chebyshev polynomial assuming that
# the coefficients have been calculated. 

procedure rcv_evcheb (coeff, x, yfit, npts, order, k1, k2)

real	coeff[ARB]		# 1D array of coefficients
real	x[npts]			# x values of points to be evaluated
real	yfit[npts]		# the fitted points
int	npts			# number of points to be evaluated
int	order			# order of the polynomial, 1 = constant
real	k1, k2			# normalizing constants

int	i
pointer	sx, pn, pnm1, pnm2
pointer sp
real	c1, c2

begin
	# fit a constant
	if (order == 1) {
	    call amovkr (coeff[1], yfit, npts)
	    return
	}

	# fit a linear function
	c1 = k2 * coeff[2]
	c2 = c1 * k1 + coeff[1]
	call altmr (x, yfit, npts, c1, c2)
	if (order == 2)
	    return

	# allocate temporary space
	call smark (sp)
	call salloc (sx, npts, TY_REAL)
	call salloc (pn, npts, TY_REAL)
	call salloc (pnm1, npts, TY_REAL)
	call salloc (pnm2, npts, TY_REAL)

	# a higher order polynomial
	call amovkr (real(1.0), Memr[pnm2], npts)
	call altar (x, Memr[sx], npts, k1, k2)
	call amovr (Memr[sx], Memr[pnm1], npts)
	call amulkr (Memr[sx], real(2.0), Memr[sx], npts)
	do i = 3, order {
	    call amulr (Memr[sx], Memr[pnm1], Memr[pn], npts)
	    call asubr (Memr[pn], Memr[pnm2], Memr[pn], npts)
	    if (i < order) {
	        call amovr (Memr[pnm1], Memr[pnm2], npts)
	        call amovr (Memr[pn], Memr[pnm1], npts)
	    }
	    call amulkr (Memr[pn], coeff[i], Memr[pn], npts)
	    call aaddr (yfit, Memr[pn], yfit, npts)
	}

	# free temporary space
	call sfree (sp)

end

# CV_EVLEG -- Procedure to evaluate a Legendre polynomial assuming that
# the coefficients have been calculated. 

procedure rcv_evleg (coeff, x, yfit, npts, order, k1, k2)

real	coeff[ARB]		# 1D array of coefficients
real	x[npts]			# x values of points to be evaluated
real	yfit[npts]		# the fitted points
int	npts			# number of data points
int	order			# order of the polynomial, 1 = constant
real	k1, k2			# normalizing constants

int	i
pointer	sx, pn, pnm1, pnm2
pointer	sp
real	ri, ri1, ri2

begin

	# fit a constant
	if (order == 1) {
	    call amovkr (coeff[1], yfit, npts)
	    return
	}

	# fit a linear function
	ri1 = k2 * coeff[2]
	ri2 = ri1 * k1 + coeff[1]
	call altmr (x, yfit, npts, ri1, ri2)
	if (order == 2)
	    return

	# allocate temporary space
	call smark (sp)
	call salloc (sx, npts, TY_REAL)
	call salloc (pn, npts, TY_REAL)
	call salloc (pnm1, npts, TY_REAL)
	call salloc (pnm2, npts, TY_REAL)

	# a higher order polynomial
	call amovkr (real(1.0), Memr[pnm2], npts)
	call altar (x, Memr[sx], npts, k1, k2)
	call amovr (Memr[sx], Memr[pnm1], npts)
	do i = 3, order {
	    ri = i
	    ri1 = (real(2.0) * ri - real(3.0)) / (ri - real(1.0))
	    ri2 = - (ri - real(2.0)) / (ri - real(1.0))
	    call amulr (Memr[sx], Memr[pnm1], Memr[pn], npts)
	    call awsur (Memr[pn], Memr[pnm2], Memr[pn], npts, ri1, ri2)
	    if (i < order) {
	        call amovr (Memr[pnm1], Memr[pnm2], npts)
	        call amovr (Memr[pn], Memr[pnm1], npts)
	    }
	    call amulkr (Memr[pn], coeff[i], Memr[pn], npts)
	    call aaddr (yfit, Memr[pn], yfit, npts)
	}

	# free temporary space
	call sfree (sp)

end

# CV_EVSPLINE1 -- Procedure to evaluate a piecewise linear spline function
# assuming that the coefficients have been calculated.

procedure rcv_evspline1 (coeff, x, yfit, npts, npieces, k1, k2)

real	coeff[ARB]		# array of coefficients
real	x[npts]			# array of x values
real	yfit[npts]		# array of fitted values
int	npts			# number of data points
int	npieces			# number of fitted points minus 1
real	k1, k2			# normalizing constants

int	j
pointer sx, tx, azindex, aindex, index
pointer	sp

begin

	# allocate the required space
	call smark (sp)
	call salloc (sx, npts, TY_REAL)
	call salloc (tx, npts, TY_REAL)
	call salloc (index, npts, TY_INT)

	# calculate the index of the first non-zero coefficient
	# for each point
	call altar (x, Memr[sx], npts, k1, k2)
	call achtri (Memr[sx], Memi[index], npts)
	call aminki (Memi[index], npieces, Memi[index], npts)

	# transform sx to range 0 to 1
	azindex = sx - 1
	do j = 1, npts {
	    aindex = azindex + j
	    Memr[aindex] = max (real(0.0), min (real(1.0), Memr[aindex] -
	        Memi[index+j-1]))
	    Memr[tx+j-1] = max (real(0.0), min (real(1.0), real(1.0) -
	        Memr[aindex]))
	}

    	# calculate yfit using the two non-zero basis function
	do j = 1, npts
	    yfit[j] = Memr[tx+j-1] * coeff[1+Memi[index+j-1]] +
		      Memr[sx+j-1] * coeff[2+Memi[index+j-1]]

        # free space
	call sfree (sp)

end

# CV_EVSPLINE3 -- Procedure to evaluate the cubic spline assuming that
# the coefficients of the fit are known.

procedure rcv_evspline3 (coeff, x, yfit, npts, npieces, k1, k2)

real	coeff[ARB]	# array of coeffcients
real	x[npts]		# array of x values
real	yfit[npts]	# array of fitted values
int	npts		# number of data points
int	npieces		# number of polynomial pieces
real	k1, k2		# normalizing constants

int	i, j
pointer	sx, tx, temp, index, sp

begin

	# allocate the required space
	call smark (sp)
        call salloc (sx, npts, TY_REAL)
	call salloc (tx, npts, TY_REAL)
	call salloc (temp, npts, TY_REAL)
	call salloc (index, npts, TY_INT)

	# calculate to which coefficients the x values contribute to
        call altar (x, Memr[sx], npts, k1, k2)
        call achtri (Memr[sx], Memi[index], npts)
        call aminki (Memi[index], npieces, Memi[index], npts)

        # transform sx to range 0 to 1
	do j = 1, npts {
	    Memr[sx+j-1] = max (real(0.0), min (real(1.0), Memr[sx+j-1] -
	        Memi[index+j-1]))
	    Memr[tx+j-1] = max (real(0.0), min (real(1.0), real(1.0) -
	        Memr[sx+j-1]))
	}

        # calculate yfit using the four non-zero basis function
	call aclrr (yfit, npts)
        do i = 1, 4 {

	    switch (i) {
	    case 1:
		call apowkr (Memr[tx], 3, Memr[temp], npts)
	    case 2:
		do j = 1, npts {
		    Memr[temp+j-1] = real(1.0) + Memr[tx+j-1] *
		        (real(3.0) + Memr[tx+j-1] * (real(3.0) -
			real(3.0) * Memr[tx+j-1]))
		}
	    case 3:
		do j = 1, npts {
		    Memr[temp+j-1] = real(1.0) + Memr[sx+j-1] *
		        (real(3.0) + Memr[sx+j-1] * (real(3.0) -
			real(3.0) * Memr[sx+j-1]))
		}
	    case 4:
		call apowkr (Memr[sx], 3, Memr[temp], npts)
	    }

	    do j = 1, npts
		Memr[temp+j-1] = Memr[temp+j-1] * coeff[i+Memi[index+j-1]]
	    call aaddr (yfit, Memr[temp], yfit, npts)
	}

	# free space
	call sfree (sp)

end