Ryacas and MaxEvalDepth

Question

I've started using R to solve a complex equation. After generating the equation I tried to solve it using Ryacas. Unfortunately, instead of giving me the result, Ryacas returns the following:

CommandLine(1) : Max evaluation stack depth reached. Please use MaxEvalDepth to increase the stack size as needed.
CommandLine(1) : Max evaluation stack depth reached. Please use MaxEvalDepth to increase the stack size as needed.

Could you please tell me how to increase that stack size through Ryacas? I've tried to do it in many ways, but I really don't know how to make use of the advice that Ryacas gave me.

===== Edit =======

So here's the code that leads to generating an equation that I want to solve.

#define net and gross values
net=10000
gross=12563.49

#construct an array for cash flows
flows=matrix(nrow=1, ncol=60)

#populate the array with cash flows
flows[c(1:60)]=c(-297.21)

#generate the equation
#flows
eq1=NULL
for (i in 1:60) {
  eq1=paste(eq1," + ", toString(flows[i]),"/((1 + x)^(",i, "/60)", ") ", collapse="")
}
#complete
equation=paste(toString(net), eq1, " == ", toString(gross), collapse="")

I then try to solve it using Solve(equation, "x").

Answer 1

This looks like an equation for an APR. Try a simple iteration like this one instead:

#inputs
instalments=60
net=12800
monthly=387.63
interest=0.1890

#function
CalculateAPR <- function(InitialPayout, InterestRate, N, MonthlyRepayment) {
  i <- InterestRate 
  repeat{
    DF <- sapply(1:N, function(N) { MonthlyRepayment/((1+i)^(N/12)) } )
    if(InitialPayout>=sum(DF)) break()
    i <- i + 0.00001
  }
return(i)
}

#output
ans=CalculateAPR(net, interest, instalments, monthly)
rm(list = c('instalments', 'interest', 'monthly', 'net'))
print(ans)

You might want to try a more efficient algorithm than this one, which simply adds 0,001% to each iteration.