cfft.F 20.9 KB
 Daniel Wortmann committed Sep 26, 2016 1 ``````#ifndef CPP_ESSL `````` Markus Betzinger committed Apr 26, 2016 2 ``````#define CPP_Singleton `````` Daniel Wortmann committed Sep 26, 2016 3 ``````#endif `````` Markus Betzinger committed Apr 26, 2016 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 ``````!You might want to undefine CPP_singleton to use essl FFT MODULE m_cfft IMPLICIT NONE CONTAINS c *************************************************************** c multivariate complex fourier transform, computed in place c using mixed-radix fast fourier transform algorithm. c by r. c. singleton, stanford research institute, oct. 1968 c arrays a and b originally hold the real and imaginary c components of the data, and return the real and c imaginary components of the resulting fourier coefficients. c multivariate data is indexed according to the fortran c array element successor function, without limit c on the number of implied multiple subscripts. c the subroutine is called once for each variate. c the calls for a multivariate transform may be in any order. c ntot is the total number of complex data values. c n is the dimension of the current variable. c nspan/n is the spacing of consucutive data values c while indexing the current variable. c the sign of isn determines the sign of the complex c exponential, and the magnitude of isn is normally one. c for a single-variate transform, c ntot = n = nspan = (number of complex data values), f.g. c call cft(a,b,n,n,n,1) c a tri-variate transform with a(n1,n2,n3), b(n1,n2,n3) c is computed by c call cft(a,b,n1*n2*n3,n1,n1,1) c call cft(a,b,n1*n2*n3,n2,n1*n2,1) c call cft(a,b,n1*n2*n3,n3,n1*n2*n3,1) c the data may alternatively be stored in a single complex c array a, then the magnitude of isn changed to two to c give the correct indexing increment and the second parameter c used to pass the initial address for the sequence of c imaginary values, e.g. c real s(2) c equivalence (a,s) c .... c .... c call cft(a,s(2),ntot,n,nspan,2) c arrays at(maxf), ck(maxf), bt(maxf), sk(maxf), and np(maxp) c are used for temporary storage. if the available storage c is insufficient, the program is terminated by a stop. c maxf must be .ge. the maximum prime factor of n. c maxp must be .gt. the number of prime factors of n. `````` Gregor Michalicek committed Nov 25, 2016 49 ``````c in addition, if the square-free portion k of n has two or `````` Markus Betzinger committed Apr 26, 2016 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 ``````c more prime factors, then maxp must be .ge. k-1. c array storage in nfac for a maximum of 11 factors of n. c if n has more than one square-free factor, the product of the c square-free factors must be .le. 210 c ******************************************************************* c array storage for maximum prime factor of 199 c the following two constants should agree with the array dimensions #ifdef CPP_Singleton SUBROUTINE cfft(a,b,ntot,n,nspan,isn) use m_juDFT IMPLICIT NONE C .. Scalar Arguments .. INTEGER isn,n,nspan,ntot C .. C .. Array Arguments .. ! REAL a(*),b(*) REAL a(ntot),b(ntot) C .. C .. Local Scalars .. REAL aa,aj,ajm,ajp,ak,akm,akp,bb,bj,bjm,bjp,bk,bkm,bkp,c1,c2,c3, + c72,cd,rad,radf,s1,s120,s2,s3,s72,sd INTEGER i,ii,inc,j,jc,jf,jj,k,k1,k2,k3,k4,kk,ks,kspan,kspnn,kt,m, + maxf,maxp,nn,nt,maxnf C .. C .. Local Arrays .. REAL, ALLOCATABLE :: at(:),bt(:),ck(:),sk(:) INTEGER, ALLOCATABLE :: nfac(:),np(:) C .. C .. Intrinsic Functions .. `````` Gregor Michalicek committed Nov 25, 2016 79 `````` INTRINSIC cos,real,mod,sin,sqrt `````` Markus Betzinger committed Apr 26, 2016 80 81 82 83 84 85 ``````C .. C .. Equivalences .. EQUIVALENCE (i,ii) C .. IF (n.LT.2) RETURN `````` Gregor Michalicek committed Nov 25, 2016 86 87 88 `````` maxf = MAX(299,n) maxp = MAX(503,n-1) maxnf = MAX(17,CEILING(sqrt(1.0*n))) `````` Markus Betzinger committed Apr 26, 2016 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 `````` ALLOCATE ( at(maxf),bt(maxf),ck(maxf),sk(maxf) ) ALLOCATE ( nfac(maxnf),np(maxp) ) inc = isn c the following constants are rad = 2.*pi , s72 = sin(0.4*pi) , c c72 = cos(0.4*pi) and s120 = sqrt(0.75) rad = 6.2831853071796 s72 = 0.95105651629515 c72 = 0.30901699437495 s120 = 0.86602540378444 IF (isn.GE.0) GO TO 10 s72 = -s72 s120 = -s120 rad = -rad inc = -inc 10 nt = inc*ntot ks = inc*nspan kspan = ks nn = nt - inc jc = ks/n radf = rad*real(jc)*0.5 i = 0 jf = 0 c determine the factors of n m = 0 k = n GO TO 30 20 m = m + 1 nfac(m) = 4 k = k/16 30 IF (k- (k/16)*16.EQ.0) GO TO 20 j = 3 jj = 9 GO TO 50 40 m = m + 1 nfac(m) = j k = k/jj 50 IF (mod(k,jj).EQ.0) GO TO 40 j = j + 2 jj = j**2 IF (jj.LE.k) GO TO 50 IF (k.GT.4) GO TO 60 kt = m nfac(m+1) = k IF (k.NE.1) m = m + 1 GO TO 100 60 IF (k- (k/4)*4.NE.0) GO TO 70 m = m + 1 nfac(m) = 2 k = k/4 70 kt = m j = 2 80 IF (mod(k,j).NE.0) GO TO 90 m = m + 1 nfac(m) = j k = k/j 90 j = ((j+1)/2)*2 + 1 IF (j.LE.k) GO TO 80 100 IF (kt.EQ.0) GO TO 120 j = kt 110 m = m + 1 nfac(m) = nfac(j) j = j - 1 IF (j.NE.0) GO TO 110 c compute fourier transform 120 sd = radf/real(kspan) cd = 2.0*sin(sd)**2 sd = sin(sd+sd) kk = 1 i = i + 1 IF (nfac(i).NE.2) GO TO 170 c transform for factor of 2 (including rotation factor) kspan = kspan/2 k1 = kspan + 2 130 k2 = kk + kspan ak = a(k2) bk = b(k2) a(k2) = a(kk) - ak b(k2) = b(kk) - bk a(kk) = a(kk) + ak b(kk) = b(kk) + bk kk = k2 + kspan IF (kk.LE.nn) GO TO 130 kk = kk - nn IF (kk.LE.jc) GO TO 130 IF (kk.GT.kspan) GO TO 360 140 c1 = 1.0 - cd s1 = sd 150 k2 = kk + kspan ak = a(kk) - a(k2) bk = b(kk) - b(k2) a(kk) = a(kk) + a(k2) b(kk) = b(kk) + b(k2) a(k2) = c1*ak - s1*bk b(k2) = s1*ak + c1*bk kk = k2 + kspan IF (kk.LT.nt) GO TO 150 k2 = kk - nt c1 = -c1 kk = k1 - k2 IF (kk.GT.k2) GO TO 150 ak = c1 - (cd*c1+sd*s1) s1 = (sd*c1-cd*s1) + s1 c the following three statements compensate for truncation c error. if rounded arithmetic is used, they may be deleted. c c1=0.5/(ak**2+s1**2)+0.5 c s1=c1*s1 c c1=c1*ak c next statement should be deleted if non-rounded arithmetic is used c1 = ak kk = kk + jc IF (kk.LT.k2) GO TO 150 k1 = k1 + inc + inc kk = (k1-kspan)/2 + jc IF (kk.LE.jc+jc) GO TO 140 GO TO 120 c transform for factor of 3 (optional code) 160 k1 = kk + kspan k2 = k1 + kspan ak = a(kk) bk = b(kk) aj = a(k1) + a(k2) bj = b(k1) + b(k2) a(kk) = ak + aj b(kk) = bk + bj ak = -0.5*aj + ak bk = -0.5*bj + bk aj = (a(k1)-a(k2))*s120 bj = (b(k1)-b(k2))*s120 a(k1) = ak - bj b(k1) = bk + aj a(k2) = ak + bj b(k2) = bk - aj kk = k2 + kspan IF (kk.LT.nn) GO TO 160 kk = kk - nn IF (kk.LE.kspan) GO TO 160 GO TO 320 c transform for factor of 4 170 IF (nfac(i).NE.4) GO TO 260 kspnn = kspan kspan = kspan/4 180 c1 = 1.0 s1 = 0 190 k1 = kk + kspan k2 = k1 + kspan k3 = k2 + kspan akp = a(kk) + a(k2) akm = a(kk) - a(k2) ajp = a(k1) + a(k3) ajm = a(k1) - a(k3) a(kk) = akp + ajp ajp = akp - ajp bkp = b(kk) + b(k2) bkm = b(kk) - b(k2) bjp = b(k1) + b(k3) bjm = b(k1) - b(k3) b(kk) = bkp + bjp bjp = bkp - bjp IF (isn.LT.0) GO TO 220 akp = akm - bjm akm = akm + bjm bkp = bkm + ajm bkm = bkm - ajm IF (s1.EQ.0.0) GO TO 230 200 a(k1) = akp*c1 - bkp*s1 b(k1) = akp*s1 + bkp*c1 a(k2) = ajp*c2 - bjp*s2 b(k2) = ajp*s2 + bjp*c2 a(k3) = akm*c3 - bkm*s3 b(k3) = akm*s3 + bkm*c3 kk = k3 + kspan IF (kk.LE.nt) GO TO 190 210 c2 = c1 - (cd*c1+sd*s1) s1 = (sd*c1-cd*s1) + s1 c the following three statements compensate for truncation c error. if rounded arithmetic is used, they may be deleted. c c1=0.5/(c2**2+s1**2)+0.5 c s1=c1*s1 c c1=c1*c2 c next statement should be deleted if non-rounded arithmetic is used c1 = c2 c2 = c1**2 - s1**2 s2 = 2.0*c1*s1 c3 = c2*c1 - s2*s1 s3 = c2*s1 + s2*c1 kk = kk - nt + jc IF (kk.LE.kspan) GO TO 190 kk = kk - kspan + inc IF (kk.LE.jc) GO TO 180 IF (kspan.EQ.jc) GO TO 360 GO TO 120 220 akp = akm + bjm akm = akm - bjm bkp = bkm - ajm bkm = bkm + ajm IF (s1.NE.0.0) GO TO 200 230 a(k1) = akp b(k1) = bkp a(k2) = ajp b(k2) = bjp a(k3) = akm b(k3) = bkm kk = k3 + kspan IF (kk.LE.nt) GO TO 190 GO TO 210 c transform for factor of 5 (optional code) 240 c2 = c72**2 - s72**2 s2 = 2.0*c72*s72 250 k1 = kk + kspan k2 = k1 + kspan k3 = k2 + kspan k4 = k3 + kspan akp = a(k1) + a(k4) akm = a(k1) - a(k4) bkp = b(k1) + b(k4) bkm = b(k1) - b(k4) ajp = a(k2) + a(k3) ajm = a(k2) - a(k3) bjp = b(k2) + b(k3) bjm = b(k2) - b(k3) aa = a(kk) bb = b(kk) a(kk) = aa + akp + ajp b(kk) = bb + bkp + bjp ak = akp*c72 + ajp*c2 + aa bk = bkp*c72 + bjp*c2 + bb aj = akm*s72 + ajm*s2 bj = bkm*s72 + bjm*s2 a(k1) = ak - bj a(k4) = ak + bj b(k1) = bk + aj b(k4) = bk - aj ak = akp*c2 + ajp*c72 + aa bk = bkp*c2 + bjp*c72 + bb aj = akm*s2 - ajm*s72 bj = bkm*s2 - bjm*s72 a(k2) = ak - bj a(k3) = ak + bj b(k2) = bk + aj b(k3) = bk - aj kk = k4 + kspan IF (kk.LT.nn) GO TO 250 kk = kk - nn IF (kk.LE.kspan) GO TO 250 GO TO 320 c transform for odd factors 260 k = nfac(i) kspnn = kspan kspan = kspan/k IF (k.EQ.3) GO TO 160 IF (k.EQ.5) GO TO 240 IF (k.EQ.jf) GO TO 280 jf = k s1 = rad/real(k) c1 = cos(s1) s1 = sin(s1) IF (jf.GT.maxf) GO TO 590 ck(jf) = 1.0 sk(jf) = 0.0 j = 1 270 ck(j) = ck(k)*c1 + sk(k)*s1 sk(j) = ck(k)*s1 - sk(k)*c1 k = k - 1 ck(k) = ck(j) sk(k) = -sk(j) j = j + 1 IF (j.LT.k) GO TO 270 280 k1 = kk k2 = kk + kspnn aa = a(kk) bb = b(kk) ak = aa bk = bb j = 1 k1 = k1 + kspan 290 k2 = k2 - kspan j = j + 1 at(j) = a(k1) + a(k2) ak = at(j) + ak bt(j) = b(k1) + b(k2) bk = bt(j) + bk j = j + 1 at(j) = a(k1) - a(k2) bt(j) = b(k1) - b(k2) k1 = k1 + kspan IF (k1.LT.k2) GO TO 290 a(kk) = ak b(kk) = bk k1 = kk k2 = kk + kspnn j = 1 300 k1 = k1 + kspan k2 = k2 - kspan jj = j ak = aa bk = bb aj = 0.0 bj = 0.0 k = 1 310 k = k + 1 ak = at(k)*ck(jj) + ak bk = bt(k)*ck(jj) + bk k = k + 1 aj = at(k)*sk(jj) + aj bj = bt(k)*sk(jj) + bj jj = jj + j IF (jj.GT.jf) jj = jj - jf IF (k.LT.jf) GO TO 310 k = jf - j a(k1) = ak - bj b(k1) = bk + aj a(k2) = ak + bj b(k2) = bk - aj j = j + 1 IF (j.LT.k) GO TO 300 kk = kk + kspnn IF (kk.LE.nn) GO TO 280 kk = kk - nn IF (kk.LE.kspan) GO TO 280 c multiply by rotation factor (except for factors of 2 and 4) 320 IF (i.EQ.m) GO TO 360 kk = jc + 1 330 c2 = 1.0 - cd s1 = sd 340 c1 = c2 s2 = s1 kk = kk + kspan 350 ak = a(kk) a(kk) = c2*ak - s2*b(kk) b(kk) = s2*ak + c2*b(kk) kk = kk + kspnn IF (kk.LE.nt) GO TO 350 ak = s1*s2 s2 = s1*c2 + c1*s2 c2 = c1*c2 - ak kk = kk - nt + kspan IF (kk.LE.kspnn) GO TO 350 c2 = c1 - (cd*c1+sd*s1) s1 = s1 + (sd*c1-cd*s1) c the following three statements compensate for truncation c error. if rounded arithmetic is used, they may c be deleted. c c1=0.5/(c2**2+s1**2)+0.5 c s1=c1*s1 c c2=c1*c2 kk = kk - kspnn + jc IF (kk.LE.kspan) GO TO 340 kk = kk - kspan + jc + inc IF (kk.LE.jc+jc) GO TO 330 GO TO 120 c permute the results to normal order---done in two stages c permutation for square factors of n 360 np(1) = ks IF (kt.EQ.0) GO TO 450 k = kt + kt + 1 IF (m.LT.k) k = k - 1 j = 1 np(k+1) = jc 370 np(j+1) = np(j)/nfac(j) np(k) = np(k+1)*nfac(j) j = j + 1 k = k - 1 IF (j.LT.k) GO TO 370 k3 = np(k+1) kspan = np(2) kk = jc + 1 k2 = kspan + 1 j = 1 IF (n.NE.ntot) GO TO 410 c permutation for single-variate transform (optional code) 380 ak = a(kk) a(kk) = a(k2) a(k2) = ak bk = b(kk) b(kk) = b(k2) b(k2) = bk kk = kk + inc k2 = kspan + k2 IF (k2.LT.ks) GO TO 380 390 k2 = k2 - np(j) j = j + 1 k2 = np(j+1) + k2 IF (k2.GT.np(j)) GO TO 390 j = 1 400 IF (kk.LT.k2) GO TO 380 kk = kk + inc k2 = kspan + k2 IF (k2.LT.ks) GO TO 400 IF (kk.LT.ks) GO TO 390 jc = k3 GO TO 450 c permutation for multivariate transform 410 k = kk + jc 420 ak = a(kk) a(kk) = a(k2) a(k2) = ak bk = b(kk) b(kk) = b(k2) b(k2) = bk kk = kk + inc k2 = k2 + inc IF (kk.LT.k) GO TO 420 kk = kk + ks - jc k2 = k2 + ks - jc IF (kk.LT.nt) GO TO 410 k2 = k2 - nt + kspan kk = kk - nt + jc IF (k2.LT.ks) GO TO 410 430 k2 = k2 - np(j) j = j + 1 k2 = np(j+1) + k2 IF (k2.GT.np(j)) GO TO 430 j = 1 440 IF (kk.LT.k2) GO TO 410 kk = kk + jc k2 = kspan + k2 IF (k2.LT.ks) GO TO 440 IF (kk.LT.ks) GO TO 430 jc = k3 450 IF (2*kt+1.GE.m) GO TO 667 kspnn = np(kt+1) c permutation for square-free factors of n j = m - kt nfac(j+1) = 1 460 nfac(j) = nfac(j)*nfac(j+1) j = j - 1 IF (j.NE.kt) GO TO 460 kt = kt + 1 nn = nfac(kt) - 1 IF (nn.GT.maxp) GO TO 590 jj = 0 j = 0 GO TO 490 470 jj = jj - k2 k2 = kk k = k + 1 kk = nfac(k) 480 jj = kk + jj IF (jj.GE.k2) GO TO 470 np(j) = jj 490 k2 = nfac(kt) k = kt + 1 kk = nfac(k) j = j + 1 IF (j.LE.nn) GO TO 480 c determine the permutation cycles of length greater than 1 j = 0 GO TO 510 500 k = kk kk = np(k) np(k) = -kk IF (kk.NE.j) GO TO 500 k3 = kk 510 j = j + 1 kk = np(j) IF (kk.LT.0) GO TO 510 IF (kk.NE.j) GO TO 500 np(j) = -j IF (j.NE.nn) GO TO 510 maxf = inc*maxf c reorder a and b, following the permutation cycles GO TO 580 520 j = j - 1 IF (np(j).LT.0) GO TO 520 jj = jc 530 kspan = jj IF (jj.GT.maxf) kspan = maxf jj = jj - kspan k = np(j) kk = jc*k + ii + jj k1 = kk + kspan k2 = 0 540 k2 = k2 + 1 at(k2) = a(k1) bt(k2) = b(k1) k1 = k1 - inc IF (k1.NE.kk) GO TO 540 550 k1 = kk + kspan k2 = k1 - jc* (k+np(k)) k = -np(k) 560 a(k1) = a(k2) b(k1) = b(k2) k1 = k1 - inc k2 = k2 - inc IF (k1.NE.kk) GO TO 560 kk = k2 IF (k.NE.j) GO TO 550 k1 = kk + kspan k2 = 0 570 k2 = k2 + 1 a(k1) = at(k2) b(k1) = bt(k2) k1 = k1 - inc IF (k1.NE.kk) GO TO 570 IF (jj.NE.0) GO TO 530 IF (j.NE.1) GO TO 520 580 j = k3 + 1 nt = nt - kspnn ii = nt - inc + 1 IF (nt.GE.0) GO TO 520 GOTO 667 c error finish, insufficient array storage 590 CONTINUE c isn = 0 WRITE (6,FMT=8000) CALL juDFT_error('array bounds exceeded',calledby ='cfft') 8000 FORMAT ('array bounds exceeded within subroutine cft') 667 CONTINUE DEALLOCATE (at,bt,ck,sk,nfac,np ) END SUBROUTINE #else SUBROUTINE cfft(a,b,ntot,n,nspan,isn) *-------------------------------------------------------------* * driver routine for ccfft subroutine instead of cfft on cray * * and dcft, dcft2 and dcft3 essl routines on IBM * *-------------------------------------------------------------* IMPLICIT NONE C ... input variables INTEGER ntot,n,nspan,isn REAL a(ntot),b(ntot) C ... local variables INTEGER i,ld1,ld2,n1,n2,n3,dimfft,idim,s(4) LOGICAL calc REAL, DIMENSION(:), ALLOCATABLE :: table, aux REAL, DIMENSION(:), ALLOCATABLE :: work, aux1, aux2 COMPLEX, DIMENSION(:), ALLOCATABLE :: x INTEGER naux,naux1,naux2,lam,la1,la2 REAL, PARAMETER :: scale = 1.0 C ... save variables SAVE n1,n2,n3 C ... data statements DATA s/1,1,1,1/ C ... now, what do we have to do ? IF ((ntot.eq.n).and.(n.eq.nspan)) THEN C ... 1D-FFT dimfft=1 n1=n n2=2 n3=2 calc=.true. ELSE IF (n.eq.nspan) THEN C ... 2D or 3D first step n1=n n2=0 calc=.false. ELSE IF (ntot.eq.nspan) THEN C ... 2D second step or 3D third step IF (n2.eq.0) THEN dimfft=2 n2=n n3=1 calc=.true. ELSE dimfft=3 n3=n calc=.true. ENDIF ELSE C ... 3D second step. n2=n calc=.false. ENDIF ENDIF ENDIF IF (calc) THEN C ... build x from a and b ALLOCATE (x(ntot)) x = (0.0,0.0) DO i=1,ntot x(i)=cmplx(a(i),b(i)) ENDDO C ... do the FFT #ifdef CPP_AIX ld1 = n1 ld2 = n1*n2 IF (dimfft.eq.1) THEN naux1 = 20000 IF (n1 > 2048) naux1 = naux1 + CEILING( 2.28*n1) ALLOCATE ( aux1(naux1), aux2(naux1) ) ELSEIF (dimfft.eq.2) THEN naux1 = 40000 + CEILING( 2.28*(n1+n2) ) IF ( max(n1, n2) <= 2048 ) naux1 = 40000 naux2 = 20000 + CEILING( (2*max(n1, n2)+256) * + (2.28 + min(64, n1, n2)) ) IF ( max(n1, n2) < 256 ) naux2 = 20000 ALLOCATE ( aux1(naux1), aux2(naux2) ) ELSE IF (dimfft.eq.3) THEN IF ( max(n2, n3) < 252 ) THEN IF (n1 <= 2048) THEN naux = 60000 ELSE naux = 60000+CEILING(4.56*n1) ENDIF ELSE la1 = CEILING( (2*n2+256)*(min(64,n1) +4.56) ) la2 = CEILING( (2*n3+256)*(min(64,n1*n2)+4.56) ) lam = max( la2 , la1 ) IF ( (n2 >= 252) .AND. (n3 < 252) ) lam = la1 IF ( (n2 < 252) .AND. (n3 >= 252) ) lam = la2 IF (n1 <= 2048) THEN naux = 60000 + lam ELSE naux = 60000+CEILING(4.56*n1)+lam ENDIF ENDIF ALLOCATE ( aux(naux) ) ENDIF #else ld1=n1 ld2=n2 s(1)=dimfft #ifndef CPP_MPI c t,j90: idim = 1024*n ALLOCATE (table(16*n+100),work(idim)) #else c t3e: idim = 2*n1*max(n2,1)*max(n3,1) ALLOCATE (table(12*(n1+n2+n3)),work(idim)) #endif #endif IF (dimfft.eq.1) THEN #ifdef CPP_AIX CALL dcft(-1, x, 1, 1, x, 1, 1, n, 1,-isn, 1.0, + aux1, naux1, aux2, naux1) CALL dcft( 0, x, 1, 1, x, 1, 1, n, 1,-isn, 1.0, + aux1, naux1, aux2, naux1) #else CALL ccfft(0,n,1.0,x,x,table,work,s) CALL ccfft(isn,n,1.0,x,x,table,work,s) #endif ENDIF IF (dimfft.eq.2) THEN #ifdef CPP_AIX CALL dcft2(-1, x, 1, n1, x, 1, n1, n1, n2,-isn, 1.0, + aux1, naux1, aux2, naux2) CALL dcft2( 0, x, 1, n1, x, 1, n1, n1, n2,-isn, 1.0, + aux1, naux1, aux2, naux2) #else CALL ccfft2d(0,n1,n2,1.0,x,ld1,x,ld1,table,work,s) CALL ccfft2d(isn,n1,n2,1.0,x,ld1,x,ld1,table,work,s) #endif ENDIF IF (dimfft.eq.3) THEN #ifdef CPP_AIX CALL dcft3(x, ld1, ld2, x, ld1, ld2, n1, n2, n3, + -isn, scale, aux, naux) #else CALL ccfft3d(0,n1,n2,n3,1.0,x,ld1,ld2,x,ld1,ld2, + table,work,s) CALL ccfft3d(isn,n1,n2,n3,1.0,x,ld1,ld2,x,ld1,ld2, + table,work,s) #endif ENDIF #ifdef CPP_AIX IF (dimfft.eq.3) THEN DEALLOCATE ( aux ) ELSE DEALLOCATE ( aux1, aux2 ) ENDIF #else DEALLOCATE (table,work) #endif C ... backup a and b DO i=1,ntot a(i)=real(x(i)) b(i)=aimag(x(i)) ENDDO DEALLOCATE (x) ENDIF END subroutine #endif END module``````