got_plt = True
except:
got_plt = False
from numpy import array
from xymath.dataset import DataSet
from xymath.nonlinfit import NonLinCurveFit
xdata = array([-2,-1.64,-1.33,-0.7,0,0.45,1.2,1.64,2.32,2.9])
ydata = array([0.699369,0.700462,0.695354,1.03905,1.97389,2.41143,
1.91091,0.919576,-0.730975,-1.42001])
DS = DataSet(xdata, ydata, xName='x', yName='y')
guessD = {'p1':1.0, 'p2':0.2}
CFit = NonLinCurveFit(DS, rhs_eqnStr='p1*cos(p2*x) + p2*sin(p1*x)',
constDinp=guessD, fit_best_pcent=0) # 0=fit best total error
print( 'residuals from XYmath = %g'%sum( (CFit.eval_xrange( xdata ) - ydata)**2 ) )
print( 'residuals from author = 0.053812696547933969' )
print('')
print(CFit.get_full_description())
if got_plt:
plt.plot( xdata, ydata, 'o', markersize=10 )
xPlotArr, yPlotArr = CFit.get_xy_plot_arrays( Npoints=100, logScale=False)
plt.plot( xPlotArr, yPlotArr )
plt.title('Trig Function: p1*cos(p2*x) + p2*sin(p1*x)')
plt.show()
