# scipy.odr.ODR¶

class scipy.odr.ODR(data, model, beta0=None, delta0=None, ifixb=None, ifixx=None, job=None, iprint=None, errfile=None, rptfile=None, ndigit=None, taufac=None, sstol=None, partol=None, maxit=None, stpb=None, stpd=None, sclb=None, scld=None, work=None, iwork=None)[source]

The ODR class gathers all information and coordinates the running of the main fitting routine.

Members of instances of the ODR class have the same names as the arguments to the initialization routine.

Parameters

instance of the Data class

modelModel class instance

instance of the Model class

Other Parameters
beta0array_like of rank-1

a rank-1 sequence of initial parameter values. Optional if model provides an “estimate” function to estimate these values.

delta0array_like of floats of rank-1, optional

a (double-precision) float array to hold the initial values of the errors in the input variables. Must be same shape as data.x

ifixbarray_like of ints of rank-1, optional

sequence of integers with the same length as beta0 that determines which parameters are held fixed. A value of 0 fixes the parameter, a value > 0 makes the parameter free.

ifixxarray_like of ints with same shape as data.x, optional

an array of integers with the same shape as data.x that determines which input observations are treated as fixed. One can use a sequence of length m (the dimensionality of the input observations) to fix some dimensions for all observations. A value of 0 fixes the observation, a value > 0 makes it free.

jobint, optional

an integer telling ODRPACK what tasks to perform. See p. 31 of the ODRPACK User’s Guide if you absolutely must set the value here. Use the method set_job post-initialization for a more readable interface.

iprintint, optional

an integer telling ODRPACK what to print. See pp. 33-34 of the ODRPACK User’s Guide if you absolutely must set the value here. Use the method set_iprint post-initialization for a more readable interface.

errfilestr, optional

string with the filename to print ODRPACK errors to. Do Not Open This File Yourself!

rptfilestr, optional

string with the filename to print ODRPACK summaries to. Do Not Open This File Yourself!

ndigitint, optional

integer specifying the number of reliable digits in the computation of the function.

taufacfloat, optional

float specifying the initial trust region. The default value is 1. The initial trust region is equal to taufac times the length of the first computed Gauss-Newton step. taufac must be less than 1.

sstolfloat, optional

float specifying the tolerance for convergence based on the relative change in the sum-of-squares. The default value is eps**(1/2) where eps is the smallest value such that 1 + eps > 1 for double precision computation on the machine. sstol must be less than 1.

partolfloat, optional

float specifying the tolerance for convergence based on the relative change in the estimated parameters. The default value is eps**(2/3) for explicit models and eps**(1/3) for implicit models. partol must be less than 1.

maxitint, optional

integer specifying the maximum number of iterations to perform. For first runs, maxit is the total number of iterations performed and defaults to 50. For restarts, maxit is the number of additional iterations to perform and defaults to 10.

stpbarray_like, optional

sequence (len(stpb) == len(beta0)) of relative step sizes to compute finite difference derivatives wrt the parameters.

stpdoptional

array (stpd.shape == data.x.shape or stpd.shape == (m,)) of relative step sizes to compute finite difference derivatives wrt the input variable errors. If stpd is a rank-1 array with length m (the dimensionality of the input variable), then the values are broadcast to all observations.

sclbarray_like, optional

sequence (len(stpb) == len(beta0)) of scaling factors for the parameters. The purpose of these scaling factors are to scale all of the parameters to around unity. Normally appropriate scaling factors are computed if this argument is not specified. Specify them yourself if the automatic procedure goes awry.

scldarray_like, optional

array (scld.shape == data.x.shape or scld.shape == (m,)) of scaling factors for the errors in the input variables. Again, these factors are automatically computed if you do not provide them. If scld.shape == (m,), then the scaling factors are broadcast to all observations.

workndarray, optional

array to hold the double-valued working data for ODRPACK. When restarting, takes the value of self.output.work.

iworkndarray, optional

array to hold the integer-valued working data for ODRPACK. When restarting, takes the value of self.output.iwork.

Attributes

The data for this fit

modelModel

The model used in fit

outputOutput

An instance if the Output class containing all of the returned data from an invocation of ODR.run() or ODR.restart()

Methods

 restart([iter]) Restarts the run with iter more iterations. Run the fitting routine with all of the information given and with full_output=1. set_iprint([init, so_init, iter, so_iter, …]) Set the iprint parameter for the printing of computation reports. set_job([fit_type, deriv, var_calc, …]) Sets the “job” parameter is a hopefully comprehensible way.

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