Missing counts during histcount?
11 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
Hi, I am randomly generating Nsim=10000 values and then binning them with histcounts but there seems to be missing values and I'm not sure where they went. I believe when I sum my histcounts
sum(Hist_CVol1)
I should be getting Nsim since it's binning each simulated value into VBinEdges, but right now I'm getting 3742 when I sum my histcounts. Not sure where they disappeared to or I'm misunderstanding what histcount does.
VBinEdges=[0 1E-17 0.3:0.05:0.8 1.1].*Vroom(:,1); %ft^3 goes to 1.1*Vroom because "infinity" to capture everything. Then we cap it later
VBinEdges_Lo=VBinEdges(1:end-1);
VBinEdges_Hi=VBinEdges(2:end);
VBinEdges_Md=VBinEdges_Lo+(diff(VBinEdges)/2);
IndEFH2 = [1:length(ExtSurgeBinEdges_Md)]'; % EFH index
IndV1 = [1:length(VBinEdges_Md)]'; %Flow volume 1 index
IndA_ps= [1:length(DamState)]'; % PS flow area index
temp1=[]; temp2=[]; temp3=[]; [temp1,temp2, temp3]=ndgrid(IndA_ps, IndV1, IndEFH2);
IndMatCVol1=[temp1(:),temp2(:), temp3(:)];
% CVol1 Node Sim
for iCombCVol1=1:size(IndMatCVol1) % iCombCVol1=1:624
% EFH loc 2 sim
EFH2_a=[]; EFH2_a=ExtSurgeBinEdges_Lo(IndMatCVol1(iCombCVol1,3));
EFH2_c=[]; EFH2_c=ExtSurgeBinEdges_Hi(IndMatCVol1(iCombCVol1,3));
pdEFH2=[]; pdEFH2=makedist('Uniform',EFH2_a,EFH2_c);
Esim2=[]; Esim2=random(pdEFH2,[Nsim,1]); %simulate external flood heights within bin (Uniform within bin)
Esim2=Esim2.*(Esim2>=0); % make sure it's positive
% Flow volume 1 sim
V1_a=[]; V1_a=VBinEdges_Lo(IndMatCVol1(iCombCVol1,2));
V1_c=[]; V1_c=VBinEdges_Hi(IndMatCVol1(iCombCVol1,2));
pdV1=[]; pdV1=makedist('Uniform',V1_a,V1_c);
V1sim=[]; V1sim=random(pdV1,[Nsim,1]);
V1sim=V1sim.*(V1sim>=0); % make sure the difference is never below zero
V1sim=V1sim.*(V1sim<=Vroom(:,1)); % make sure the difference is always below Vroom
%Flow volume 2 sim
% PS state sim through area
Mu_ps=[]; Mu_ps=Amean_ps(IndMatCVol1(iCombCVol1,1));
Sig_ps=[]; Sig_ps=0.2*Mu_ps;
pd_Asim_ps=[]; pd_Asim_ps = makedist('normal',Mu_ps,Sig_ps);
Asim_ps = []; Asim_ps=random(pd_Asim_ps,[Nsim,1]);
Asim_ps(Asim_ps<0)=0; % make sure the area is postive
Asim_ps(Asim_ps>A_ps)=A_ps; %make sure area is never bigger than the full area
% Volumetric flow rate 2 sim calculation
Qsim_ps2=[]; Qsim_ps2=Cd.*Asim_ps.*sqrt(2*g*(Esim2-n_ps)); %ft^3/s
Qsim_ps2(Esim2<=n_ps)=1E-20; %No flow when Esim is less than or equal to installation height
% Flow volume sim calculation
Vsim_ps2=[]; Vsim_ps2=Qsim_ps2.*Dsim; %ft^3
Vsim_ps2=Vsim_ps2.*(Vsim_ps2<=Vroom(:,1)); %Ensure Vsim is less than Vroom (3 Vroom configs)
Vsim_ps2(Esim2<=n_ps)=1E-20; %No flow when Esim is less than or equal to installation height
% Cumulative flow 1 sim calculation
CVol1sim= V1sim+Vsim_ps2;
% PMF
Hist_CVol1=[]; [Hist_CVol1,~] = histcounts(CVol1sim,VBinEdges);
Hist_CVol1=Hist_CVol1';
PMF_CVol1(:,iCombCVol1)=Hist_CVol1./sum(Hist_CVol1); % Bins it by the parents
end
2 Kommentare
Image Analyst
am 30 Aug. 2023
I tried to reproduce and I just got "Unrecognized function or variable 'Vroom'." What is that function?
Antworten (1)
Voss
am 30 Aug. 2023
I suspect that the data you are using histcounts on has elements outside the range of bin edges you have specified.
For example:
% generate 10000 samples from a standard normal distribution
d = makedist('normal',0,1);
x = random(d,[10000,1]);
size(x)
% specify some edges that don't include +/- infinity.
% the domain of normal distributions is (-Inf,Inf)
e = [0 1E-17 0.3:0.05:0.8 1.1];
% do the histogram binning
N = histcounts(x,e);
% count the number of samples within the specified bins:
N_inside = sum(N)
% count the number of samples outside the specified bins,
% either below the first edge or above the last edge:
N_outside = nnz(x < e(1) | x > e(end))
% the total number of samples:
N_inside + N_outside
3 Kommentare
Voss
am 31 Aug. 2023
Those lines work to limit the values of each vector, but you do histcounts on the sum of two of those vectors:
CVol1sim = V1sim+Vsim_ps2;
[Hist_CVol1,~] = histcounts(CVol1sim,VBinEdges);
It looks to me like there's no guarantee that all elements of CVol1sim are within the range of VBinEdges. In fact, it looks like CVol1sim could be as high as 2*Vroom(:,1).
Voss
am 31 Aug. 2023
By the way, this logic:
V1sim=V1sim.*(V1sim<=Vroom(:,1));
sets the elements of V1sim that are greater than Vroom(:,1) to zero (or NaN if the element was Inf). Is that what you want to do?
Here's an example:
Vroom = 6250;
V1sim = [-Inf -1000 0 1 7000 Inf]
V1sim=V1sim.*(V1sim<=Vroom(:,1))
I imagine you want to set those elements that are greater than Vroom(:,1) to Vroom(:,1), in which case, you can use logic like you have in other places:
V1sim = [-Inf -1000 0 1 7000 Inf]
V1sim(V1sim > Vroom(:,1)) = Vroom(:,1)
(This doesn't address the original question or impact my suggestion that elements sent to histcounts are outside the range of the bin edges.)
Siehe auch
Kategorien
Mehr zu Data Distribution Plots finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!