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c@427
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1 /* idamax.f -- translated by f2c (version 20061008).
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c@427
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2 You must link the resulting object file with libf2c:
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c@427
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3 on Microsoft Windows system, link with libf2c.lib;
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c@427
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4 on Linux or Unix systems, link with .../path/to/libf2c.a -lm
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c@427
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5 or, if you install libf2c.a in a standard place, with -lf2c -lm
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c@427
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6 -- in that order, at the end of the command line, as in
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7 cc *.o -lf2c -lm
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8 Source for libf2c is in /netlib/f2c/libf2c.zip, e.g.,
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9
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10 http://www.netlib.org/f2c/libf2c.zip
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11 */
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12
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13 #include "f2c.h"
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c@427
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14 #include "blaswrap.h"
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15
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16 integer idamax_(integer *n, doublereal *dx, integer *incx)
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17 {
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c@427
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18 /* System generated locals */
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c@427
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19 integer ret_val, i__1;
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c@427
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20 doublereal d__1;
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21
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c@427
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22 /* Local variables */
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c@427
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23 integer i__, ix;
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c@427
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24 doublereal dmax__;
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25
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c@427
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26 /* .. Scalar Arguments .. */
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c@427
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27 /* .. */
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c@427
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28 /* .. Array Arguments .. */
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c@427
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29 /* .. */
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30
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c@427
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31 /* Purpose */
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c@427
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32 /* ======= */
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33
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c@427
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34 /* finds the index of element having max. absolute value. */
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c@427
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35 /* jack dongarra, linpack, 3/11/78. */
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c@427
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36 /* modified 3/93 to return if incx .le. 0. */
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c@427
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37 /* modified 12/3/93, array(1) declarations changed to array(*) */
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38
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39
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c@427
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40 /* .. Local Scalars .. */
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c@427
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41 /* .. */
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c@427
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42 /* .. Intrinsic Functions .. */
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c@427
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43 /* .. */
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c@427
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44 /* Parameter adjustments */
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c@427
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45 --dx;
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46
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c@427
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47 /* Function Body */
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48 ret_val = 0;
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c@427
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49 if (*n < 1 || *incx <= 0) {
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c@427
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50 return ret_val;
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c@427
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51 }
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c@427
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52 ret_val = 1;
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c@427
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53 if (*n == 1) {
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c@427
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54 return ret_val;
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c@427
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55 }
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c@427
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56 if (*incx == 1) {
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c@427
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57 goto L20;
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c@427
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58 }
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c@427
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59
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c@427
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60 /* code for increment not equal to 1 */
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61
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c@427
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62 ix = 1;
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c@427
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63 dmax__ = abs(dx[1]);
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c@427
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64 ix += *incx;
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c@427
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65 i__1 = *n;
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c@427
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66 for (i__ = 2; i__ <= i__1; ++i__) {
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c@427
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67 if ((d__1 = dx[ix], abs(d__1)) <= dmax__) {
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c@427
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68 goto L5;
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c@427
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69 }
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c@427
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70 ret_val = i__;
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c@427
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71 dmax__ = (d__1 = dx[ix], abs(d__1));
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c@427
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72 L5:
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c@427
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73 ix += *incx;
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c@427
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74 /* L10: */
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c@427
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75 }
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c@427
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76 return ret_val;
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c@427
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77
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c@427
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78 /* code for increment equal to 1 */
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c@427
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79
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c@427
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80 L20:
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c@427
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81 dmax__ = abs(dx[1]);
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c@427
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82 i__1 = *n;
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c@427
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83 for (i__ = 2; i__ <= i__1; ++i__) {
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c@427
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84 if ((d__1 = dx[i__], abs(d__1)) <= dmax__) {
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c@427
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85 goto L30;
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c@427
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86 }
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c@427
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87 ret_val = i__;
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c@427
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88 dmax__ = (d__1 = dx[i__], abs(d__1));
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c@427
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89 L30:
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c@427
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90 ;
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c@427
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91 }
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c@427
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92 return ret_val;
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c@427
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93 } /* idamax_ */
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