I am getting the following error message, any help is appreciated: ERROR: (execution) Character argument should be numeric. operation : QUAD at line 6707 column 5 operands  : *LIT1021, INTERVAL *LIT1021      1 row       1 col     (character, size 6) TLAINT INTERVAL      1 row       2 cols    (character, size 2) H  K1 statement : CALL at line 6707 column 5 traceback : module KBETAFIND at line 6707 column 5 Below is the code: PROC IML;   START TLAINT(U) GLOBAL(N1,NMAX,Z1,C,ZBETA); /*THIS MODULE CREATES THE INTEGRAND TO BE SOLVED;*/ Z1 = J(1,1,.);   TEMP = Z1[1,1]*SQRT((N1+NMAX)/N1)-C;   ZB = TEMP><ZBETA;   AA1 = C*(C+ZB)-U**2;   AA2 = SQRT((C+ZB)**2-U**2);   ARG = AA1/AA2;   YY1 = CDF("NORMAL",ARG);   YY = YY1*PDF("NORMAL",U);   RETURN(YY);   FINISH TLAINT; START KBETAFIND(A) GLOBAL(N1,NMAX,C,ZBETA,H,ALPHA,Z1); /*THIS MODULE SOLVES K AND ZBETA GIVEN N1,NMAX, C AND ZBETA;*/ ALPHA = 0.025; C = J(1,1,.); KMAX = J(1,1,.); K = A[1]; ZBETA = A[2]; KMAX = C+ZBETA; K1 = MIN(K,KMAX);   INTERVAL = {H K1};   CALL QUAD(INT,"TLAINT", INTERVAL);   FUTILE = 1 - CDF("NORMAL",H);   FF = INT - (FUTILE - ALPHA);   RETURN (FF); FINISH KBETAFIND; START PWRCAL(Z1) GLOBAL(C,ZBBTA,N1,NMAX,N2,DELTA,S); /*THIS MODULE CREATES THE INTEGRAND TO CALCULATE UNCONDITIONAL POWER;*/ /*WILL NEED TO BE CALLED IN WITHIN DO LOOP*/   ZBBTA=ZZ_;   S = SQRT(2/N1);   N2 = ((((C+ZBBTA)**2)/(Z1**2) -1)*N1)><NMAX;   CPARG = (C*SQRT(N1+N2) - Z1*SQRT(N1) - N2*DELTA/SQRT(2))/SQRT(N2);   PWRARG = (1-CDF("NORMAL",CPARG))*PDF("NORMAL",Z1-DELTA/S);   RETURN PWRARG; FINISH PWRCAL; HH = T(DO(.7,1.2,(1.2-.7)/49)); NMAX_=J(NROW(HH),1,.); UNP  =J(NROW(HH),1,.); CPOWER  =J(NROW(HH),1,.); NTMAX = 192;   DO I = 1 TO NROW(HH);   H = HH[I,1];   FUTILE = 1 - CDF("NORMAL",H);   N1 = 40;   NMAX = NTMAX - N1;   NMAX_ = NMAX;   DO WHILE (UNP<0.8);   N1 = N1+1;   S = SQRT(2/N1);   NMAX= NTMAX - N1;   NMAX_ = NMAX;   OPTN = {2,4}`;   CALL NLPTR(RC,XR,"KBETAFIND",{2, 0.8}`,OPTN) ;   KVAL = XR[1]; ZBBTA = XR[2];   CALL QUAD(INT,"PWRCAL",HH[I,1]||KVAL);   UNP = CDF("NORMAL",DELTA/S - KVAL) + INT;    END;   NS1 = N1;   START EXPN(Z1) GLOBAL(NS1,C,ZBBTA,NMAX,DELTA);   S = SQRT(2/NS1);   EN_ = ((((C+ZBBTA)**2)/(Z1**2) -1)*NS1)><NMAX;   F = EN_*PDF("NORMAL",Z1-DELTA/S);   FINISH EXPN;   CALL QUAD(ENINT,"EXPN",HH[I,1]||KVAL);   EN = NS1 + ENINT;   CPOWER = CDF("NORMAL",ZBBTA);   PRINT "ITERATION" I;   END;   CREATE FINAL VAR{HH,KVAL,CPOWER,NS1,EN,NMAX_};   APPEND;   CLOSE FINAL; QUIT; ... View more