how to store repeated elements in an array

I have 2 responses , one SOAP and one REST. I need to compare the two values and check if they match . I created an an array to store the SOAP taxlots but when I try to log it, it gives an error

so SOAP response is something like this .  

Security 1

      Taxlot 

      Taxlot

Security2

     Taxlot

Security3

     Taxlot 

REST response is 

Security 1Taxlot

Security 1Taxlot

Security2 Taxlot

Security3 Taxlot

I have been able to read the taxlots for each security in SOAP. I want to store them in a matrix

something like taxlot[1], taxlot[2]...

The number of taxlots are dependent on another field called row count. So I want to use a for loop and store the values .

I tried something like below

secIndex is for security count

taxlotids is the number of taxlot for each security

j is to store the taxlots in an array

def j=0 

for (def secIndex=1;secIndex<val;secIndex++)
{
def securities=holder.getNodeValues( "//gl:SampleResponse/SecurityList/SecurityInformation[$secIndex]/SecurityNumber[1]")

log.info securities.toString()  // logs the security number

def taxlotids =holder.getNodeValues( "//gl:SampleResponse/SecurityList/SecurityInformation[$secIndex]/TaxLotList[1]/TaxLotInformation").length

log.info taxlotids // logs the number of taxlots for each security 

int taxlotidsi=taxlotids+1

def matrix= []

for (def ti=1;ti<taxlotidsi;ti++)

{

def termval= holder.getNodeValues( "//gl:SampleResponse/SecurityList/SecurityInformation[$secIndex]/TaxLotList[1]/TaxLotInformation[$ti]/GainLossForTaxLot[1]/Term[1]" )   // This gets the Taxlotfield

matrix[j]=termval  //Creating an array to store these taxlots. Not sure if its the right way

log.info matrix[j].toString() 

j++  //incrementing the array counter
log.info j
}
}

log.info matrix[2]   ------ I want to log the value of second taxlot but this gives an error