CORAN85.DOC                        


             The new (May 1985) Correspondence Analysis program (CORAN85
        in  the following) no longer requires transposition of the image
        set.  A sequential file is created, the records of which contain
        the  NPIX  pixels passed by the mask.  One record is created for
        each image, in the order the images are  entered.   Two  options
        are    available:     In-Core    computation    and   Stochastic
        approximation.

             When the in-core option is selected, the entire  matrix  of
        dimension  NPIX  x  NPIX is stored in core.  Because of this, it
        should not be used for projects involving more than  200  pixels
        in  the mask.  The method of stochastic approximation, developed
        by Lebart specifically to accomodate large data sets,  works  by
        going through the sequential file in seven passes, taking random
        samples of the pixels.

             CORAN85 is implemented, in modular form, as part of SPIDER.
        At present, there are eight operations:

             CA_SI    Initializes CORAN by preparing a sequential 
                      file.  No background correction used. 

             CA_SIB   as 'CA_SI', but with background correction.

             CA_S     Runs CORAN, using sequential file created by
                      either 'CA_SI' or 'CA_SIB', and puts the
                      results into image-coordinate file, pix-
                      coordinate file, and eigenvector file.  

             CA_SM    prints out selected factor maps, either of
                      image coordinates or of pixel coordinates.

             CA_SME   types out list of eigenvalues in addition to
                      printing the map.  (If only eigenvalues are
                      desired, answer "(P)ixel or (I)mage coor-
                      dinates" with any symbol other than 'P' or
                      'I'.)

             CA_SR    reconstitutes selected images using a subset
                      of the eigenvectors.

             CA_SRD   produces differential reconstituted images
                      (i.e., the O-factor image has been subtracted).

             CA_SRI   produces importance images (i.e., differential
                      reconstituted images without weighting of the
                      pixels).


             The auxiliary files  containing  image  coordinates,  pixel
        coordinates,  and  eigenvectors are sequential.  All coordinates
        are stored as floating point numbers.



            Subroutines called by UTIL1              Directory         OLB
            ======================================   ==========       ======
            JPMSK1.FOR   (CA_S, CA_SI, CA_SIB)       .FORTRAN]         REAL
            SGRAF.FOR    (CA_SM, CA_SME)             .FORTRAN]         JP
            JPMSK2.FOR   (CA_SR, CA_SRD, CA_SRI)     .FORTRAN]         REAL


          Subroutine   Called by   Stored in           Purpose
         ============ =========== =========== ===========================
           BORNS        HPLAN        HPLAN     Finds extreme values of 
                                               array
           CPROJ        STOCHA       STOC
           DOGRAF
           EPUR4        HPLAN        HPLAN    Collapses map according to
                                               S.D. multiple
           GETCOO       SCOR         STOC     Computes coos and distances
                                               for rows and columns
           GETSPE
           GSMOD        ITPOW        STOC     Gram-Schmidt orthonormal-
                                               ization
           HPLAN        SGRAF1       GRAPH
           IMSEQ4       JPMSK2       JPMSK2   Selects images
           INCORE                    STOC     Driver of CA in-core
           ITPOW        STOCHA       STOC     Iterated power method
           MSKDEC                    JPMSK2   Decodes mask array
           RECDUM       JPMSK2       RECDUM   Reconstitutes dummy images
                                               using factor coordinates
                                               supplied
           RECONS       JPMSK2       RECONS    Reconstitute selected image
                                               set
           REW                       REW      Rewinds and skips header
           SCOR         SCORAN       STOC     Driver of CA/analysis
           SCORAN                    SCORAN   Driver of CA/memory 
                                               management
           SEN3A                     STOC     Uniform pseudo random 
                                               generator
           SGRAF                     SGRAF    Driver of graphic output
           SGRAF1       SGRAF        SGRAF    Graphic output organizer
           SRIP2        SRIPE        SRIPE
           SRIPE        JPMSK2       SRIPE    Initialize RCONS, perform
                                               reconstitution
           STOCHA       SCOR         STOC     Driver of CA/analysis/
                                               stochastic
           TRIDI                     STOC
           VPROP     /  CPROJ        STOC
                     \  INCORE       
           JPMSK1                    JPMSK1   Driver of sequential file
                                               preparation from SPIDER
                                               files and CORAN analysis
           JPMSK2                    JPMSK2   Driver of reconstitution
                                               of SPIDER images
                                                                   Page 3



             List of source files:

                Name            Compile         Library
                ===========     ============    ================
                HPLAN           I4              [SCOR]JP
                JPMSK1          I2              [SPIDER]REAL
                JPMSK2          I2              REAL
                RECONS          I4              JP
                RECDUM          I4              JP
                REW             I4              JP
                SGRAF           I2              REAL
                SRIPE           I4              JP
                STOC            I4              JP