Formula: chi ~ A * sin((2 * pi)/128 * t + B)

Parameters:
   Estimate Std. Error t value Pr(>|t|)    
A 34.370745   0.240202  143.09   <2e-16 ***
B -0.196677   0.006989  -28.14   <2e-16 ***
---
Signif. codes:  0 `***' 0.001 `**' 0.01 `*' 0.05 `.' 0.1 ` ' 1 

Residual standard error: 5.435 on 1022 degrees of freedom

Correlation of Parameter Estimates:
           A
B -4.682e-09


parameters from fft of signal
A =  34.37076  ;   B =  -0.0985027