Implement NEHRP 2020 Factory

Matlab code for computing sms, sm1

function [ SMs, SM1, SaM, SaDM ] = SMsSM1_Calculator_Ver190319( DetLL, SaMD, SaMP, T, Vs30 )

% Written by Sanaz Rezaeian 3/19/2019

%%% Input:
% DetLL: Deterministic Lower Limit (Det Floor)
    % a vector of size 22 (i.e., 22periods) for a given site class 
% SaMD: Maximum Direction Deterministic Ground Motion (without DetLL floor)
    % a vector of size 22 (i.e., 22periods) for a given site class 
% SaMP: Maximum Direction x Risk Targeted Ground Motion (Probabilistic GM)
    % a vector of size 22 (i.e., 22periods) for a given site class 
% T: a vector of the 22 periods (sec)
    % T = [0 0.01 0.02 0.03 0.05 0.075 0.1 0.15 0.2 0.25 0.3 0.4 0.5 0.75 1 1.5 2 3 4 5 7.5 10];
% Vs30: Vs30 of the site class (m/s)
    % {'A','AB','B','BC','C','CD','D','DE','E'} = [2000 1500 1080 760 530 365 260 185 150] m/s
    
%%% Output:
% SMs: Short period ground motion 
    % a scalar for the given site class
    % in previous design codes: SMs=(Fa)x(Ss)=(Fa)x(min[(S_SUH x C_RS),S_SD])
% SM1: Long period ground motion
    % a scalar for the given site class
    % in previous design codes: SM1=(Fv)x(S1)=(Fv)x(min[(S_1UH x C_1S),S_1D])
% SaM: MultiPeriod Response Spectrum 
    % a vector of size 22 for the given site class
% SaDM: Design Response Spectrum (2/3 x SaM)
    % a vector of size 22 for the given site class
%----------------------------------------------------------------------

% Calculate SaM: Cap ProbSpectrum w/ floored DetSpectrum (at every T)
    flooredSaMD = max(DetLL,SaMD);
    SaM = min(SaMP,flooredSaMD);  
    
% Calculate SMs:
    a = find(T==0.2);
    b = find(T==5);
    SMs = 0.9*(max(SaM(a:b)));

% Calculate SM1:
    if Vs30>365.76  %m/s
         a = find(T==1);
         b = find(T==2);
         SM1 = max(T(a:b).*SaM(a:b));
     else
         a = find(T==1);
         b = find(T==5);
         SM1 = max(T(a:b).*SaM(a:b));
     end

% Calculate SaDM:
    SaDM = 2/3 * SaM;