Calculate number appearance within a range

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Ancalagon8 2023-1-19

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https://ww2.mathworks.cn/matlabcentral/answers/1896925-calculate-number-appearance-within-a-range

评论： Star Strider 2023-1-25

I need help calculating the number of times a number appears within a range. To be more specific, I need to specify how many times TT values are between [1, 2], then between (2, 10], then between (10, 20], then between (20, 50] then between and (50, 100].

classes=[1 2 10 20 50 100];
count=hist(TT,classes); 

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Answer 1

Star Strider 2023-1-19

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https://ww2.mathworks.cn/matlabcentral/answers/1896925-calculate-number-appearance-within-a-range#answer_1151960

在 MATLAB Online 中打开

The histcounts and histogram functions are perfect for this —

LD = load(websave('TT','https://www.mathworks.com/matlabcentral/answers/uploaded_files/1268555/TT.mat'));

TT = LD.TT

TT = 31×1

0 1.0000 14.9000 8.7000 1.0000 0 0 0 40.2000 10.3000

Edges = [1 2 10 20 50 100];

[BinCounts,Edges,Bin] = histcounts(TT, Edges);

BinCounts

BinCounts = 1×5

2 4 5 4 0

figure

histogram(TT, Edges)

xticks(Edges)

grid

xlim([min(Edges) max(Edges)])

xlabel('Bin Limits')

ylabel('Counts')

Thi histogram plot gives a better depiction of the bin limits than a bar plot of the histcounts results would.

.

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Star Strider 2023-1-19

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As always, my pleasure!

One approach would be to define the upper limit of ‘Edges’ as Inf (or any other suitably large number such as realmax) however Inf is essentially limitless —

LD = load(websave('TT','https://www.mathworks.com/matlabcentral/answers/uploaded_files/1268555/TT.mat'));

TT = LD.TT

TT = 31×1

0 1.0000 14.9000 8.7000 1.0000 0 0 0 40.2000 10.3000

Edges = [1 2 10 20 50 100 Inf];

[BinCounts,Edges,Bin] = histcounts(TT, Edges);

BinCounts

BinCounts = 1×6

2 4 5 4 0 0

BinAssignments = table(TT, Bin)

BinAssignments = 31×2 table

TT Bin ____ ___ 0 0 1 0 14.9 3 8.7 2 1 0 0 0 0 0 0 0 40.2 4 10.3 3 0 0 0 0 0.1 0 3.7 2 1.3 1 0 0

figure

histogram(TT, Edges)

xticks(Edges)

grid

xlim([min(Edges) max(Edges)])

xlabel('Bin Limits')

Ax = gca;

Ax.XAxis.TickLabelRotation = 45;

Ax.XAxis.FontSize = 7;

ylabel('Counts')

Setting the upper limit to Inf makes the tick labels difficult to see if they are close together.

.

Star Strider 2023-1-19

在 MATLAB Online 中打开

Using my previous Comment code with the current ‘Edges’ vector —

LD = load(websave('t','https://www.mathworks.com/matlabcentral/answers/uploaded_files/1267645/t.mat'));

t = LD.t

t = 513077×1 timetable

date_time Rain __________________ ____ 01-Jan-19 00-00-00 0 01-Jan-19 00-03-00 0 01-Jan-19 00-04-00 0 01-Jan-19 00-05-00 0 01-Jan-19 00-06-00 0 01-Jan-19 00-07-00 0 01-Jan-19 00-08-00 0 01-Jan-19 00-09-00 0 01-Jan-19 00-10-00 0 01-Jan-19 00-11-00 0 01-Jan-19 00-12-00 0 01-Jan-19 00-13-00 0 01-Jan-19 00-14-00 0 01-Jan-19 00-15-00 0 01-Jan-19 00-16-00 0 01-Jan-19 00-17-00 0

Rainmax = max(t.Rain)

Rainmax = 4.3000

Rainmin = min(t.Rain(t.Rain>0))

Rainmin = 0.1000

%Monthly timetables from t

for a = 1:12

MMidx = month(t.date_time) == a;

tMonth{a,:} = t(MMidx,:);

end

tMonth

tMonth = 12×1 cell array

{42923×1 timetable} {40027×1 timetable} {44449×1 timetable} {43114×1 timetable} {44542×1 timetable} {41875×1 timetable} {43988×1 timetable} {44233×1 timetable} {42688×1 timetable} {44173×1 timetable} {40673×1 timetable} {40392×1 timetable}

% tMonth{1}

Edges = [1 2 10 20 50 100 Inf]; % Change As Necessary To Produce The Desired REsults

Cntrs = Edges(1:end-1)+diff(Edges)/2;

for k = 1:numel(tMonth)

[BinCounts,~,Bin] = histcounts(tMonth{k}.Rain, Edges, 'Normalization','probability');

Nv{k,:} = BinCounts;

Binv{:,k} = Bin;

MMM{k} = month(tMonth{k}.date_time(1,:),'shortname');

end

Nv

Nv = 12×1 cell array

{[ 2.5627e-04 0 0 0 0 0]} {[ 0 0 0 0 0 0]} {[ 0 0 0 0 0 0]} {[ 0 0 0 0 0 0]} {[ 2.2451e-05 0 0 0 0 0]} {[ 0 0 0 0 0 0]} {[ 0 0 0 0 0 0]} {[ 0 0 0 0 0 0]} {[ 4.6852e-05 0 0 0 0 0]} {[ 0 0 0 0 0 0]} {[9.8345e-04 9.8345e-05 0 0 0 0]} {[ 0 0 0 0 0 0]}

% Binmin = min(cellfun(@(x)min(x(x>0)),Nv, 'Unif',0))

% Binmax = max(cellfun(@max,Nv, 'Unif',0))

figure

tiledlayout(6,2, 'TileSpacing','compact')

for k = 1:numel(tMonth)

nexttile

bar(Cntrs, Nv{k}, 'FaceColor','flat', 'EdgeColor','flat')

grid

ylabel(MMM{k})

ylim([1E-5 1]) % Optional, Change To Produce The Desired Result

set(gca,'YScale','log') % Optional (Shows Detail), Change To Produce The Desired Result

end

xlabel('Bin Centers')

The lower llimit of the ‘Edges’ vector is now set to 1, and several months have days with less that 1, so all the bins for those months are empty. (I commented-out ‘Binmin’ and ‘Binmax’ because they only calculate minima greater than 0 and since several months have essentially empty bins, this would require returning empty values for those months. These variables are simply for my benefit in understanding the data anyway, and are not necessary for, or used in, the code otherwise.)

.

Star Strider 2023-1-20

在 MATLAB Online 中打开

Yes!

Try this —

LD = load(websave('t','https://www.mathworks.com/matlabcentral/answers/uploaded_files/1267645/t.mat'));

t = LD.t

t = 513077×1 timetable

date_time Rain __________________ ____ 01-Jan-19 00-00-00 0 01-Jan-19 00-03-00 0 01-Jan-19 00-04-00 0 01-Jan-19 00-05-00 0 01-Jan-19 00-06-00 0 01-Jan-19 00-07-00 0 01-Jan-19 00-08-00 0 01-Jan-19 00-09-00 0 01-Jan-19 00-10-00 0 01-Jan-19 00-11-00 0 01-Jan-19 00-12-00 0 01-Jan-19 00-13-00 0 01-Jan-19 00-14-00 0 01-Jan-19 00-15-00 0 01-Jan-19 00-16-00 0 01-Jan-19 00-17-00 0

Rainmax = max(t.Rain)

Rainmax = 4.3000

Rainmin = min(t.Rain(t.Rain>0))

Rainmin = 0.1000

%Monthly timetables from t

for a = 1:12

MMidx = month(t.date_time) == a;

tMonth{a,:} = t(MMidx,:);

end

tMonth

tMonth = 12×1 cell array

{42923×1 timetable} {40027×1 timetable} {44449×1 timetable} {43114×1 timetable} {44542×1 timetable} {41875×1 timetable} {43988×1 timetable} {44233×1 timetable} {42688×1 timetable} {44173×1 timetable} {40673×1 timetable} {40392×1 timetable}

% tMonth{1}

Edges = [1 2 10 20 50 100 Inf]; % Change As Necessary To Produce The Desired REsults

Cntrs = Edges(1:end-1)+diff(Edges)/2;

for k = 1:numel(tMonth)

[BinCounts,~,Bin] = histcounts(tMonth{k}.Rain, Edges, 'Normalization','probability');

Nv{k,:} = BinCounts;

Binv{:,k} = Bin;

MMM{k,:} = month(tMonth{k}.date_time(1,:),'shortname');

end

% MMM

% TQ = cell2table(MMM)

Nv

Nv = 12×1 cell array

{[ 2.5627e-04 0 0 0 0 0]} {[ 0 0 0 0 0 0]} {[ 0 0 0 0 0 0]} {[ 0 0 0 0 0 0]} {[ 2.2451e-05 0 0 0 0 0]} {[ 0 0 0 0 0 0]} {[ 0 0 0 0 0 0]} {[ 0 0 0 0 0 0]} {[ 4.6852e-05 0 0 0 0 0]} {[ 0 0 0 0 0 0]} {[9.8345e-04 9.8345e-05 0 0 0 0]} {[ 0 0 0 0 0 0]}

% Binmin = min(cellfun(@(x)min(x(x>0)),Nv, 'Unif',0))

% Binmax = max(cellfun(@max,Nv, 'Unif',0))

figure

tiledlayout(6,2, 'TileSpacing','compact')

for k = 1:numel(tMonth)

nexttile

bar(Cntrs, Nv{k}, 'FaceColor','flat', 'EdgeColor','flat')

grid

ylabel(MMM{k})

ylim([1E-5 1]) % Optional, Change To Produce The Desired Result

set(gca,'YScale','log') % Optional (Shows Detail), Change To Produce The Desired Result

end

xlabel('Bin Centers')

Frequencies = array2table(cell2mat(Nv), 'RowNames',[MMM{:}], 'VariableNames',{'[1, 2]','(2, 10]','(10, 20]','(20, 50]','(50, 100]','(100 Inf]'})

Frequencies = 12×6 table

[1, 2] (2, 10] (10, 20] (20, 50] (50, 100] (100 Inf] __________ __________ ________ ________ _________ _________ Jan 0.00025627 0 0 0 0 0 Feb 0 0 0 0 0 0 Mar 0 0 0 0 0 0 Apr 0 0 0 0 0 0 May 2.2451e-05 0 0 0 0 0 Jun 0 0 0 0 0 0 Jul 0 0 0 0 0 0 Aug 0 0 0 0 0 0 Sep 4.6852e-05 0 0 0 0 0 Oct 0 0 0 0 0 0 Nov 0.00098345 9.8345e-05 0 0 0 0 Dec 0 0 0 0 0 0

Since I remember that you recently upgraded to R2022b, this should work.

The number of variable names has to be the same as the number of variables, so I added the last class.

I added the months as 'RowNames' although you can also add them as a separate variable (or not include them at all) if you prefer, since I converted them to a column vector in this version of my code. If you want to use full month names instead, replace 'shortname' with 'name' in the ‘MMM’ assignment in the first loop.

You should be able to write the ‘Frequencies’ table to the Excel file. (I did not do that experiment.)

.

Askic V 2023-1-25

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@Star Strider can you please explain, how you upload file and use load command in th code, just like in the example

load(websave('TT','https://www.mathworks.com/matlabcentral/answers/uploaded_files/1268555/TT.mat'));

Star Strider 2023-1-25

@Askic V — That is exactly how I do it, although I always load into a output variable so that I have some control over what loads, and so I can change the name of the variable used in the subsequent script if necessary. (Since I rarely use websave, credit for discovering this goes to @Karim, who was appropriately rewarded for discovering it.)

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Answer 2

Askic V 2023-1-19

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在 MATLAB Online 中打开

Perhaps this code snippet will help you:

load TT
classes = [1 2 10 20 50 100];
tol = 1e-10;
res = zeros(size(diff(classes)));
for i = 1:numel(classes)-1
    res(i) = sum(TT >= classes(i)-tol & TT < classes(i+1)+tol);
end
res

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Calculate number appearance within a range

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Calculate number appearance within a range

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