CSR.c

//
//  csr.c
//  Bratu-C
//
//  Created by Tim Ioannidis on 12/19/11.
//  Copyright 2011 Chemeng NTUA. All rights reserved.
//

#include <stdio.h>
#include <math.h> 
#include "structs.h"
#include "extern.h"
#include "parameters.h"
#include "methods_decl.h"


void CSR(int nell,struct common2 *elem1,struct common4 *sparse,double value,int i,int j,int *ncod)
{
    int k=0,l=0,t=0,update=0,temp=0;
    temp=sparse->IA[i];
    //Dirichlet boundary condition
    if ((ncod[i]==1) && (i!=j)){
        value=0;
    }
    else if ((ncod[i]==1) && (i==j) && (sparse->AA[temp]!=1)) {
        value=1;
    }
    else if ((ncod[i]==1)   &&  (i==j)  && (sparse->AA[temp]==1)){
        value=0;
    }    
    //ksekinaei i eisagwgi
    if (value!=0) {
        if (sparse->AA[temp]==0) {
            sparse->AA[temp]=value;
            sparse->JA[temp]=j;
            (Nz)++;
        }
        else if(sparse->AA[temp]!=0){
            t=sparse->IA[i];
            while (t<(sparse->IA[i+1])) {
                if (sparse->JA[t]==j) {
                    update=1;
                    break;
                }
                t++;
            }
        }
        if (update==1) {
            sparse->AA[t]+=value;
        }
        else {
            if (((sparse->AA[temp])!=0) && ((sparse->JA[temp])<j)) {
                k=temp;
                while ((sparse->JA[k]<j) && (k<(sparse->IA[i+1]))) {
                    k++;
                }
                for (l=(sparse->IA[elem1->nop[nell][8]]+8); l>=k; l--) {
                    sparse->AA[l+1]=sparse->AA[l];
                    sparse->JA[l+1]=sparse->JA[l];
                }
                sparse->AA[k]=value;
                sparse->JA[k]=j;
                for (k=(i+1); k<N+1; k++) {
                    sparse->IA[k]++;    
                }
                (Nz)++;
            }
        }
    }
}