problem regarding calling a function with multiple arguments

i tried to call a function in different ways but i received different errors at each time.the following are each attempt and related error

1.

[spktimes, {nspikes}] = SGfast([dt, nrep], rate, {deadtime, refracparams})

Error: File: test.m Line: 89 Column: 12
An array for multiple LHS assignment cannot contain expressions.

so i removed {}for nspikes:

2.

[spktimes, nspikes] = SGfast([dt, nrep], rate, {deadtime, refracparams})

and got this error:

Error using SGfast
The third argument must be a real, double-precision scalar.

so again removed{} for third input argument as well:

3.

[spktimes, nspikes] = SGfast([dt, nrep], rate, deadtime, refracparams);

and received this error:

Error using SGfast
Requires two or three input arguments.

[Walter Roberson]

Duplicates http://www.mathworks.co.uk/matlabcentral/answers/89356-problem-with-function-argument and needs to be merged into there.