Retracting the time-tags from the histcounts

A histogram (number of time-tags per unit bin) was created using "histcoounts" for a series of time-tags (first picture). After creating histogram, I put the threshold (300) on the count such that the values below the 300 shall get deleted. And the time-tags should be retractable for those values that were above the threshold. Could you please help me with getrting the values of time-tags from the second picture?

[Dyuman Joshi]

You can use the max() function -

y = 1:10

y = 1×10

1 2 3 4 5 6 7 8 9 10

thresh = 5;
z = max(y, thresh)

z = 1×10

5 5 5 5 5 6 7 8 9 10

Answer 1

[Dyuman Joshi]

If you are working with R2019a or a later version, use readmatrix and writematrix. Otherwise, use writetable

D=readmatrix('timetags.txt');

%transposing as histcounts() returns a row vector
D1=histcounts(D, 'NumBins', 200).';
subplot(2,1,1);
plot(D1)

subplot(2,1,2);
D2=D1;
D2(D2<300)=[];
plot(D2)

%write data to a text file
writematrix(D2, 'tagtime.txt')

%check the contents of the file
type tagtime.txt

305
381
588
675
498
505
437
574
427
443
831
444
1134
418
406
376
337
366
383
369
602
1053
337
338
377
417
384
343
388
321
325
363
359
446
1088
397
300
304
333
566
524
438
387
432
355
1067
306
604
673
509
519
469
448
329
1027
855
325
896
712
733
354
331
408
578
786
640
311
307

[Manoj Kumar V]

Thank You. I see the data value is generated from your code. But, I need to ectract the time-tags values of remaining values.

[Dyuman Joshi]

In that case -

D=readmatrix('timetags.txt');

%transposing as histcounts() returns a row vector
D1=histcounts(D, 'NumBins', 200).';
subplot(2,1,1);
plot(D1)

subplot(2,1,2);
idx = D1>300;
D2 = D1(idx);
plot(D2)

%write data to a text file
writematrix(D2, 'tagtime_extracted.txt')

%Remaining vales
D3 = D1(~idx);
writematrix(D3, 'tagtime_remaining.txt')

%check the contents of the file
type tagtime_extracted.txt

305
381
588
675
498
505
437
574
427
443
831
444
1134
418
406
376
337
366
383
369
602
1053
337
338
377
417
384
343
388
321
325
363
359
446
1088
397
304
333
566
524
438
387
432
355
1067
306
604
673
509
519
469
448
329
1027
855
325
896
712
733
354
331
408
578
786
640
311
307

type tagtime_remaining.txt

279
215
193
187
266
213
188
170
215
177
283
179
202
216
253
260
116
209
261
197
153
174
230
142
223
166
221
231
165
136
154
159
120
180
152
135
201
202
151
156
208
208
231
250
154
220
211
276
209
221
300
280
229
224
223
251
277
283
220
236
229
259
286
248
214
253
223
253
295
195
182
151
183
186
158
194
235
167
154
191
231
285
192
163
173
126
157
141
150
177
252
245
245
217
242
169
242
202
244
236
254
281
290
270
221
235
213
238
226
152
187
265
281
229
223
155
157
159
231
261
275
195
149
214
199
192
161
210
240
281
248
231
240

[Manoj Kumar V]

Hi, Plot due to histcounts is created from 62110 timetags cells. After removing the values below the threshold, remaining timetags cells are 33961. I would like to read out all these 33961 timetags.

[Dyuman Joshi]

Okay, you want the corresponding original data. Check this -

D=readmatrix('timetags.txt');

%Get the bin counts and the bin indices of the data
[D1,~,k]=histcounts(D, 'NumBins', 200)

D1 = 1×200

305 381 588 675 498 505 437 574 427 443 831 444 1134 418 406 376 337 366 383 369 602 1053 337 338 377 417 384 343 388 279

k = 62110×1

1 1 1 1 1 1 1 1 1 1

subplot(2,1,1);
plot(D1)

subplot(2,1,2);
%Indices of bin counts with value greater than 300
idx = find(D1>300);
D2 = D1(idx);
plot(D2)

%Compare the indices to index of each element of original data
z = ismember(k, idx);


out_extracted = D(z)

out_extracted = 33961×1

1.0e+13 * 1.4248 1.4248 1.4248 1.4248 1.4248 1.4248 1.4248 1.4248 1.4248 1.4248

Use writematrix to save the extracted data as I have shown above.

[Dyuman Joshi]

Any updates @Manoj Kumar V?

[Manoj Kumar V]

I am yet to solve this question. In brief, my question is, I would like to see all those time-tags at the output which are not being deleted from the histcounts.

[Dyuman Joshi]

That is what I have done here - https://in.mathworks.com/matlabcentral/answers/2082553-retracting-the-time-tags-from-the-histcounts#comment_3067268

Did you not check my comment?

[Manoj Kumar V]

Yes. I could not find the timetags values as output.

Answer 2

[Image Analyst]

Try setting those counts to nan. Then they won't show up. Something like

data = 5000 * rand(1, 5000);
subplot(1, 2, 1);
[counts, binEdges] = histcounts(data);
plot(binEdges(1:end-1), counts, 'b-')
yline(300, 'r-')
counts(counts <= 300) = nan;
subplot(1, 2, 2)
plot(binEdges(1:end-1), counts)
grid on;

[Manoj Kumar V]

Thank you for the answer. I would like to elaborate my question.

Attached text document contains the timetags data. I prefer to create histogram of 200 bins of the time-tags. and remove the values below 300 (on y-axis) from the histogram. And then I want to get the time-tags values back of the un-deleted values in a text file. How can I do that?

[Alexander]

Could you supply the data and code for your picture above?

[Manoj Kumar V]

Data (in txt format) and matlab code are attached below.