function Ca = AnsiZ136MPEComputeCa(stimulusWavelengthNm) % Ca = AnsiZ136MPEComputeCa(stimulusSizeDeg) % % **************************************************************************** % IMPORTANT: Before using the AnsiZ136 routines, please see the notes on usage % and responsibility in PsychAnsiZ136MPE/Contents.m (type "help PsychAnsiZ136MPE" % at the Matlab prompt. % **************************************************************************** % % Compute constant Ca, ANSI Z136.1-2007, Table 6, p. 76. % % This is only defined between 400 and 1400 nm. % % 2/20/13 dhb Wrote it. %% Implement formula. if (stimulusWavelengthNm < 400) error('Ca not defined for wavelengths less than 400 nm'); elseif (stimulusWavelengthNm >= 400 && stimulusWavelengthNm < 700) Ca = 1; elseif (stimulusWavelengthNm >= 700 && stimulusWavelengthNm < 1050) Ca = 10^(2*(stimulusWavelengthNm/1000-0.700)); elseif (stimulusWavelengthNm >= 1050 && stimulusWavelengthNm < 1400) Ca = 5; else error('Ca not defined for wavelengths greater than or equal to 1400 nm'); end end