SLATM7 computes the entries of D as specified by MODE


    COND and IRSIGN. IDIST and ISEED determine the generation


    of random numbers. SLATM7 is called by SLATMT to generate


    random test matrices.

  MODE   - INTEGER


           On entry describes how D is to be computed:


           MODE = 0 means do not change D.


           MODE = 1 sets D(1)=1 and D(2:RANK)=1.0/COND


           MODE = 2 sets D(1:RANK-1)=1 and D(RANK)=1.0/COND


           MODE = 3 sets D(I)=COND**(-(I-1)/(RANK-1)) I=1:RANK


           MODE = 4 sets D(i)=1 - (i-1)/(N-1)*(1 - 1/COND)


           MODE = 5 sets D to random numbers in the range


                    ( 1/COND , 1 ) such that their logarithms


                    are uniformly distributed.


           MODE = 6 set D to random numbers from same distribution


                    as the rest of the matrix.


           MODE < 0 has the same meaning as ABS(MODE), except that


              the order of the elements of D is reversed.


           Thus if MODE is positive, D has entries ranging from


              1 to 1/COND, if negative, from 1/COND to 1,


           Not modified.


  COND   - REAL


           On entry, used as described under MODE above.


           If used, it must be >= 1. Not modified.


  IRSIGN - INTEGER


           On entry, if MODE neither -6, 0 nor 6, determines sign of


           entries of D


           0 => leave entries of D unchanged


           1 => multiply each entry of D by 1 or -1 with probability .5


  IDIST  - CHARACTER*1


           On entry, IDIST specifies the type of distribution to be


           used to generate a random matrix .


           1 => UNIFORM( 0, 1 )


           2 => UNIFORM( -1, 1 )


           3 => NORMAL( 0, 1 )


           Not modified.


  ISEED  - INTEGER array, dimension ( 4 )


           On entry ISEED specifies the seed of the random number


           generator. The random number generator uses a


           linear congruential sequence limited to small


           integers, and so should produce machine independent


           random numbers. The values of ISEED are changed on


           exit, and can be used in the next call to SLATM7


           to continue the same random number sequence.


           Changed on exit.


  D      - REAL array, dimension ( MIN( M , N ) )


           Array to be computed according to MODE, COND and IRSIGN.


           May be changed on exit if MODE is nonzero.


  N      - INTEGER


           Number of entries of D. Not modified.


  RANK   - INTEGER


           The rank of matrix to be generated for modes 1,2,3 only.


           D( RANK+1:N ) = 0.


           Not modified.


  INFO   - INTEGER


            0  => normal termination


           -1  => if MODE not in range -6 to 6


           -2  => if MODE neither -6, 0 nor 6, and


                  IRSIGN neither 0 nor 1


           -3  => if MODE neither -6, 0 nor 6 and COND less than 1


           -4  => if MODE equals 6 or -6 and IDIST not in range 1 to 3


           -7  => if N negative

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