Thread: getting wrong output

im guessing its when it comes to culculating the initial vector, as u can see from the out put.....

New vector:
y[1]=[89806308033758335519957510699863969348510599027283 42001933875355046869783389222623707753599574476432 94137672174519651927335372003439184892435557960885 10866209917577152863227861185710903110831001937129 87506259980859399539001668422094856393681307990309 76439107536483051236436899063108141629011245169671 88791296.000000 -11225788504219791939994688837482996168563824878410 42750241734419380858722923652827963469199946809554 11767209021814956490916921500429898111554444745110 63858276239697144107903482648213862888853875242141 23438282497607424942375208552761857049210163498788 72054888442060381404554612382888517703626405646208 985989120.000000 44903154016879167759978755349931984674255299513641 71000966937677523434891694611311853876799787238216 47068836087259825963667686001719592446217778980442 55433104958788576431613930592855451555415500968564 93753129990429699769500834211047428196840653995154 88219553768241525618218449531554070814505622584835 94395648.000000 -22451577008439583879989377674965992337127649756820 85500483468838761717445847305655926938399893619108 23534418043629912981833843000859796223108889490221 27716552479394288215806965296427725777707750484282 46876564995214849884750417105523714098420326997577 44109776884120762809109224765777035407252811292417 97197824.000000 ]
The length of this vector is: Inf
Normalized new vector:
x[1]=[0.000000 -0.000000 0.000000 -0.000000 ]


New vector:
y[2]=[0.000000 0.000000 0.000000 0.000000 ]
The length of this vector is: 0.000000
Normalized new vector:
x[2]=[NaN NaN NaN NaN ]

then it continues to y[10] and all i get is NaN from y2 to y10
i cant figure out what is wrong with it....here is the part of the code i feel might need fixing.
insert

Code:

for(n=0;n<=3;n++) printf("%f ",x[n]);printf("]\n");
 for(k=1;k<=10;k++) 
  {
   for(n=0;n<=3;n++) x[n]=z[n];
     matrix_mult(K,x,y,4); 
     printf("\nNew vector:\ny[%d]=[",k);
   for(n=0;n<=3;n++) printf("%f ",y[n]);
     printf("] \nThe length of this vector is: %f\n",unit_norm(y,4));
   for(n=0;n<=3;n++) z[n]=y[n]/unit_norm(y,4);
     printf("Normalized new vector:\nx[%d]=[",k);
   for(n=0;n<=3;n++) printf("%f ",z[n]); 
     printf("] \n\n");
  }
}


void matrix_mult(double a[4][4],double b[4],double c[4],int rows)
{
   int k;
   double dot_p;
 for(rows=0;rows<4;rows++)
  {
   for(k=0,dot_p=0.;k<4;k++) dot_p +=a[rows][k]*b[k];
     c[rows]=dot_p;
  }
   return;
}

double unit_norm(double vec[4],int cols)
{
   double sum;
   sum=sqrt(pow(vec[0],2)+pow(vec[1],2)+pow(vec[2],2)+pow(vec[3],2));
   return sum;