C LAP 10
C ..................................................................LAP 20
C LAP 30
C SUBROUTINE LAP LAP 40
C LAP 50
C PURPOSE LAP 60
C COMPUTE THE VALUES OF THE LAGUERRE POLYNOMIALS L(N,X) LAP 70
C FOR ARGUMENT VALUE X AND ORDERS 0 UP TO N. LAP 80
C LAP 90
C USAGE LAP 100
C CALL LAP(Y,X,N) LAP 110
C LAP 120
C DESCRIPTION OF PARAMETERS LAP 130
C Y - RESULT VECTOR OF DIMENSION N+1 CONTAINING THE VALUESLAP 140
C OF LAGUERRE POLYNOMIALS OF ORDER 0 UP TO N LAP 150
C FOR GIVEN ARGUMENT X. LAP 160
C VALUES ARE ORDERED FROM LOW TO HIGH ORDER LAP 170
C X - ARGUMENT OF LAGUERRE POLYNOMIAL LAP 180
C N - ORDER OF LAGUERRE POLYNOMIAL LAP 190
C LAP 200
C REMARKS LAP 210
C N LESS THAN 0 IS TREATED AS IF N WERE 0 LAP 220
C LAP 230
C SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED LAP 240
C NONE LAP 250
C LAP 260
C METHOD LAP 270
C EVALUATION IS BASED ON THE RECURRENCE EQUATION FOR LAP 280
C LAGUERRE POLYNOMIALS L(N,X) LAP 290
C L(N+1,X)=2*L(N,X)-L(N-1,X)-((1+X)*L(N,X)-L(N-1,X))/(N+1), LAP 300
C WHERE THE FIRST TERM IN BRACKETS IS THE ORDER, LAP 310
C THE SECOND IS THE ARGUMENT. LAP 320
C STARTING VALUES ARE L(0,X)=1, L(1,X)=1.-X. LAP 330
C LAP 340
C ..................................................................LAP 350
C LAP 360
SUBROUTINE LAP(Y,X,N) LAP 370
C LAP 380
DIMENSION Y(1) LAP 390
C LAP 400
C TEST OF ORDER LAP 410
Y(1)=1. LAP 420
IF(N)1,1,2 LAP 430
1 RETURN LAP 440
C LAP 450
2 Y(2)=1.-X LAP 460
IF(N-1)1,1,3 LAP 470
C LAP 480
C INITIALIZATION LAP 490
3 T=1.+X LAP 500
C LAP 510
DO 4 I=2,N LAP 520
4 Y(I+1)=Y(I)-Y(I-1)+Y(I)-(T*Y(I)-Y(I-1))/FLOAT(I) LAP 530
RETURN LAP 540
END LAP 550