# Changeset 1221196 in sasview for src/sas/sasgui/perspectives/pr/media/pr_help.rst

Ignore:
Timestamp:
Jan 27, 2017 3:58:23 PM (6 years ago)
Branches:
master, ESS_GUI, ESS_GUI_Docs, ESS_GUI_batch_fitting, ESS_GUI_bumps_abstraction, ESS_GUI_iss1116, ESS_GUI_iss879, ESS_GUI_iss959, ESS_GUI_opencl, ESS_GUI_ordering, ESS_GUI_sync_sascalc, costrafo411, magnetic_scatt, release-4.1.1, release-4.1.2, release-4.2.2, ticket-1009, ticket-1094-headless, ticket-1242-2d-resolution, ticket-1243, ticket-1249, ticket885, unittest-saveload
Children:
b61bd57
Parents:
51f1c347
Message:

fix transpose typo in year

File:
1 edited

### Legend:

Unmodified
 r0391dae ----------- This tool calculates a real-space distance distribution function, *P(r)*, using the inversion approach (Moore, 1908). This tool calculates a real-space distance distribution function, *P(r)*, using the inversion approach (Moore, 1980). *P(r)* is set to be equal to an expansion of base functions of the type \chi^2=\frac{\sum_i (I_{meas}(Q_i)-I_{th}(Q_i))^2}{error^2}+Reg\_term where $I_{meas}(Q_i)$ is the measured scattering intensity and $I_{th}(Q_i)$ is the prediction from the Fourier transform of the *P(r)* expansion. the prediction from the Fourier transform of the *P(r)* expansion. The $Reg\_term$ term is a regularization term set to the second derivative The $Reg\_term$ term is a regularization term set to the second derivative $d^2P(r)/d^2r$ integrated over $r$. It is used to produce a smooth *P(r)* output. *  *Number of terms*: the number of base functions in the P(r) expansion. *  *Regularization constant*: a multiplicative constant to set the size of the regularization term.