/usr/share/psychtoolbox-3/PsychRadiometric/Obsolete/RadianceToRetIrradiance.m is in psychtoolbox-3-common 3.0.12.20160126.dfsg1-1ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 | function irradianceWattsPerUm2 = RadianceToRetIrradiance(radianceWattsPerM2Sr,radianceS,pupilAreaMm2,eyeLengthMm)
% irradianceWattsPerUm2 = RadianceToRetIrradiance(radianceWattsPerM2Sr,radianceS,pupilAreaMm2,eyeLengthMm)
%
% Perform the geometric calculations necessary to convert a measurement of source
% radiance to corresponding retinal irradiance.
%
% Input radianceWattsPerM2Sr should be in units of power/m^2-sr-wlinterval.
% Input radianceS gives the wavelength sampling information.
% Input pupilAreaMm2 should be in units of mm^2.
% Input eyeLengthMm should be the length of the eye in mm.
% Output irradianceWattsPerUm2 is in units of power/um^2-wlinterval.
%
% Light power may be expressed in watts or quanta-sec or in your
% favorite units. Indeed, it may also be passed as energy rather
% than power.
%
% This conversion does not take absorption in the eye into account,
% as this is more conveniently foldeded into the spectral absorptance.
%
% See also: RadianceAndPupilAreaEyeLengthToRetIrradiance, radPupilAreaFromLum, EyeLength, RetIrradianceToRadiance.
%
% Note: This routine is now obsolete, as it mixes radiometric and unit conversions. Preferred is to
% use RadianceAndPupilAreaEyeLengthToRetIrradiance and then take charge of your units in your
% calling code.
%
% 7/10/03 dhb Wrote it.
% 11/06/03 dhb Fixed comments about units, as per Lu Yin email.
% 3/29/12 dhb Comment on output units was wrong. It said power/um^2-sec-wlinterval
% but the 'sec' part makes no sense given the 'power' in the numerator.
% 2/28/13 dhb Make units clear in variable names.
% 3/6/13 dhb Rewrite to use new conversion function. Move to Obsolete directory.
% dhb Also improved variable naming.
%% Make sure we didn't break anything?
CHECKAGAINSTOLDCODE = 1;
%% Convert radiance units to match eye length and pupil units
radianceWattsPerMm2Sr = radianceWattsPerM2Sr*1e-6;
%% Convert to ret irradiance
irradianceWattsPerMm2 = RadianceAndPupilAreaEyeLengthToRetIrradiance(radianceWattsPerMm2Sr,radianceS,pupilAreaMm2,eyeLengthMm);
%% Convert irradiance units to uM2.
irradianceWattsPerUm2 = irradianceWattsPerMm2*1e-6;
%% Check what we get now against the original implementation
if (CHECKAGAINSTOLDCODE)
% Convert spectral units to power/sr-mm^2-wlinterval
radianceWattsPerMm2SrCheck = radianceWattsPerM2Sr*1e-6;
% Define factor to convert radiance spectrum to retinal irradiance in watts/mm^2-wlinterval.
% Commented out code shows the logic, which is short circuited by actual code.
% but is conceptually convenient for doing the calculation.
% distanceToSourceMm = 100;
% fractionfSphere = pupilAreaMm2/4*pi*distanceToSourceMm^2;
% pupilAreaSR = 4*pi*fractionOfSphere;
% sourceAreaMm = (distanceToSourceMm^2)/(eyeLengthMm^2);
% conversionFactor = pupilAreaSR*sourceAreaMm;
conversionFactor = pupilAreaMm2/(eyeLengthMm^2);
irradianceWattsPerMm2Check = conversionFactor*radianceWattsPerMm2SrCheck;
% Convert units to um^2 from mm^2 base.
irradianceWattsPerUm2Check = irradianceWattsPerMm2Check*1e-6;
% Check
if (abs(irradianceWattsPerUm2 - irradianceWattsPerUm2Check) > 1e-16)
error('New and old ways of computing this quantity do not agree. Oops!');
end
end
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