readme updates

minor refactoring

Author: jacobwilliams

README.md

@@ -33,4 +33,6 @@ The Minpack source code and related files and documentation are distributed unde
 ### References
   * Original sourcecode from: [Netlib](https://www.netlib.org/minpack/)
   * J. J. Moré, B. S. Garbow, and K. E. Hillstrom, [User Guide for MINPACK-1](http://cds.cern.ch/record/126569/files/CM-P00068642.pdf), Argonne National Laboratory Report ANL-80-74, Argonne, Ill., 1980.
-  * J. J. Moré, D. C. Sorensen, K. E. Hillstrom, and B. S. Garbow, The MINPACK Project, in Sources and Development of Mathematical Software, W. J. Cowell, ed., Prentice-Hall, pages 88-111, 1984.
+  * J. J. Moré, D. C. Sorensen, K. E. Hillstrom, and B. S. Garbow, The MINPACK Project, in Sources and Development of Mathematical Software, W. J. Cowell, ed., Prentice-Hall, pages 88-111, 1984.
+  * M. J. D. Powell, A Hybrid Method for Nonlinear Equations. Numerical Methods for Nonlinear Algebraic Equations, P. Rabinowitz, editor. Gordon and Breach, 1970.
+  * Jorge J. More, The Levenberg-Marquardt Algorithm, Implementation and Theory. Numerical Analysis, G. A. Watson, editor. Lecture Notes in Mathematics 630, Springer-Verlag, 1977.

test/test_lmder.f90

@@ -1,8 +1,6 @@
-
       program test
          use minpack_module
       implicit none
-
 !     **********
 !
 !     THIS PROGRAM TESTS CODES FOR THE LEAST-SQUARES SOLUTION OF
@@ -34,7 +32,7 @@ program test
       double precision factor , fnorm1 , fnorm2 , one , ten , tol
       double precision fjac(65,40) , fnm(60) , fvec(65) , wa(265) ,     &
                      & x(40)
-            external fcn
+      external fcn
       common /refnum/ NPRob , NFEv , NJEv
 !
 !     LOGICAL INPUT UNIT IS ASSUMED TO BE NUMBER 5.

test/test_lmstr.f90

@@ -45,7 +45,7 @@ program test
       data nread , nwrite/5 , 6/
 !
       data one , ten/1.0d0 , 1.0d1/
-      tol = dsqrt(dpmpar(1))
+      tol = sqrt(dpmpar(1))
       ldfjac = 40
       lwa = 265
       ic = 0
@@ -249,7 +249,7 @@ subroutine ssqjac(m,n,x,Fjac,Ldfjac,Nprob)
          tpi = eight*datan(one)
          temp = x(1)**2 + x(2)**2
          tmp1 = tpi*temp
-         tmp2 = dsqrt(temp)
+         tmp2 = sqrt(temp)
          Fjac(1,1) = c100*x(2)/tmp1
          Fjac(1,2) = -c100*x(1)/tmp1
          Fjac(1,3) = ten
@@ -270,11 +270,11 @@ subroutine ssqjac(m,n,x,Fjac,Ldfjac,Nprob)
          enddo
          Fjac(1,1) = one
          Fjac(1,2) = ten
-         Fjac(2,3) = dsqrt(five)
+         Fjac(2,3) = sqrt(five)
          Fjac(2,4) = -Fjac(2,3)
          Fjac(3,2) = two*(x(2)-two*x(3))
          Fjac(3,3) = -two*Fjac(3,2)
-         Fjac(4,1) = two*dsqrt(ten)*(x(1)-x(4))
+         Fjac(4,1) = two*sqrt(ten)*(x(1)-x(4))
          Fjac(4,4) = -Fjac(4,1)
       case (7)
 !
@@ -834,7 +834,7 @@ subroutine ssqfcn(m,n,x,Fvec,Nprob)
          tmp1 = dsign(zp25,x(2))
          if ( x(1)>zero ) tmp1 = datan(x(2)/x(1))/tpi
          if ( x(1)<zero ) tmp1 = datan(x(2)/x(1))/tpi + zp5
-         tmp2 = dsqrt(x(1)**2+x(2)**2)
+         tmp2 = sqrt(x(1)**2+x(2)**2)
          Fvec(1) = ten*(x(3)-ten*tmp1)
          Fvec(2) = ten*(tmp2-one)
          Fvec(3) = x(3)
@@ -843,9 +843,9 @@ subroutine ssqfcn(m,n,x,Fvec,Nprob)
 !     POWELL SINGULAR FUNCTION.
 !
          Fvec(1) = x(1) + ten*x(2)
-         Fvec(2) = dsqrt(five)*(x(3)-x(4))
+         Fvec(2) = sqrt(five)*(x(3)-x(4))
          Fvec(3) = (x(2)-two*x(3))**2
-         Fvec(4) = dsqrt(ten)*(x(1)-x(4))**2
+         Fvec(4) = sqrt(ten)*(x(1)-x(4))**2
       case (7)
 !
 !     FREUDENSTEIN AND ROTH FUNCTION.