I have a script that cumulates my data and plots it afterwards. In my case my data are temperatures and the plots show the number of hours a year in which these temperatures and every temperature below are reached.
For example:
in 7500 hours a year it is 25 degree and colder
in 6000 hours a year it is 20 degree and colder
I get the result that i need using the matlab scrpit below:
filenameTRY2035='TZ10.dat';
daten = dlmread(filenameTRY2035);
TZ10 = sort(daten(1:length(daten)));
A = length(TZ7); A = A';
% plot
figure(1)
clf(1)
hold on;
h1 = plot(TZ10,A);
Now I want the temperatures counted the other way around.
For example:
in 1000 hours a year its 25 degrees and hotter
in 3500 hours a year it is 20 degrees and hotter
Could anyone help me modify my script in the way that I get the plots I need?
Thanks a lot,
Cheyenne
So let's say you have
TZ10 =
.... 7000 7300 7500 ....
7500 -> 25° or colder
7300 -> 24° or colder
7000 -> 23° or colder
...
And there are 8766 hours in a year.
Then the reversed order would be
l = length(TZ10);
TZ10_reverse(l) = 8766 - TZ10(1)
for temp = 2:l
TZ10_reverse(l - temp + 1) = (8766 - TZ10(temp)) + (TZ10(temp) - TZ10(temp - 1));
end
Because if there are 8766 hours a year and 7500 hours equals or colder than 25° a year, then there are 8766 - 7500 strictly warmer than 25° a year and TZ10(25) - TZ10(24) days equals to 25°
I also did it in order to get it sorted!
By the way....
TZ10 = sort(daten(1:length(daten)));
is equivalent to
TZ10 = sort(daten);
The elements of daten from 1 to the max index of daten is basicly daten itself!
Related
I am trying to analyze timeseries of wheel turns that were sampled at 1 minute intervals for 10 days. t is a 1 x 14000 array that goes from .1666 hours to 240 hours. analysis.timeseries.(grp).(chs) is a 1 x 14000 array for each of my groups of interest and their specific channels that specifize activity at each minute sampled. I'm interested in collecting the maximum power and the frequency it occurs at. My problem is I'm not sure what units f is coming out in. I would like to have it return in cycles per hour and span to a maximum period of 30 hours. I tried to use the Galileo example in the documentation as a guide, but it didn't seem to work.
Below is my code:
groups = {'GFF' 'GMF' 'SFF' 'SMF'};
chgroups = {chnamesGF chnamesGM chnamesSF chnamesSM};
t1 = (t * 3600); %matlab treats this as seconds so convert it to an hour form
onehour = seconds(hours(1));
for i = 1:4
grp = groups{1,i};
chn = chgroups{1,i};
for channel = 1:length(chn)
chs = chn{channel,1};
[pxx,f]= plomb(analysis.timeseries.(grp).(chs),t, 30/onehour,'normalized');
analysis.pxx.(grp).(chs) = pxx;
analysis.f.(grp).(chs) = f;
analysis.lsp.power.(grp).(chs) = max(pxx);
[row,col,v] = find(analysis.pxx.(grp).(chs) == analysis.lsp.power.(grp).(chs));
analysis.lsp.tau.(grp).(chs) = analysis.f.(grp).(chs)(row);
end
end
Not really an answer but it is hard to put a image in a comment.
Judging by this (plomb manual matlab),
I think that pxx is without dimension as for f is is the frequency so 1/(dimension of t) dimension. If your t is in hours I would say h^-1.
So I'd rather say try
[pxx,f]= plomb(analysis.timeseries.(grp).(chs),t*30.0/onehour,'normalized');
I'm trying to convert an array of milliseconds and its respective data. However I want to do so in hours and minutes.
Millis = [60000 120000 180000 240000....]
Power = [ 12 14 12 13 14 ...]
I've set it up so the data records every minute, hence the 60000 millis (= 1 minimte). I am trying to plot time on the x axis and power on the y. I would like to have the x axis displayed in hours and minutes with each respective power data corresponding to its respective time.
I've tried this
for i=2:length(Millis)
Conv2Min(i) = Millis(i) / 60000;
Time(i) = startTime + Conv2Min(i);
if (Time(i-1) > Time(i) + 60)
Time(i) + 100;
end
end
s = num2str(Time);
This in attempt to turn the milliseconds into hours starting at 08:00 and once 60 minutes have past going to 09:00, the problem is plotting this. I get a gap between 08:59 and 09:00. I also cannot maintain the 0=initial 0.
In this scenario it is preferable to work with datenum values and then use datetick to set the format of the tick labels of your plot to 'HH:MM'.
Let's suppose that you started taking measurements at t_1 = [HH_1, MM_1] and stopped taking measurements at t_2 = [HH_2, MM_2].
A cool trick to generate the array of datenum values is to use the following expression:
time_datenums = HH_1/24 + MM_1/1440 : 1/1440 : HH_2/24 + MM_2/1440;
Explanation:
We are creating a regularly-spaced vector time_datenums = A:B:C using the colon (:) operator, where A is the starting datenum value, B is the increment between datenum values and C is the ending datenum value.
Since your measurements have been taken every minute (60000 milliseconds), then the increment between datenum values should be of 1 minute too. As a day has 24 hours, that makes 1440 minutes a day, so use B = 1/1440 as the increment between vector elements, to get 1 minute increments.
For A and C we simply need to divide the hour digits by 24 and the minute digits by 1440 and sum them up like this:
A = HH_1/24 + MM_1/1440
C = HH_2/24 + MM_2/1440
So for example, if t_1 = [08, 00], then A = 08/24 + 00/1440. As simple as that.
Notice that this procedure doesn't use the datenum function at all, and still, it manages to generate a valid array of datenum values only taking into consideration the time of the datenum, without needing to bother about the date of the datenum. You can learn more about this here and here.
Going back to your original problem, let's have a look at the code:
time_millisec = 0:60000:9e6; % Time array in milliseconds.
power = 10*rand(size(time_millisec)); % Random power data.
% Elapsed time in milliseconds.
elapsed_millisec = time_millisec(end) - time_millisec(1);
% Integer part of elapsed hours.
elapsed_hours_int = fix(elapsed_millisec/(1000*60*60));
% Fractional part of elapsed hours.
elapsed_hours_frac = (elapsed_millisec/(1000*60*60)) - elapsed_hours_int;
t_1 = [08, 00]; % Start time 08:00
t_2 = [t_1(1) + elapsed_hours_int, t_1(2) + elapsed_hours_frac*60]; % Compute End time.
HH_1 = t_1(1); % Hour digits of t_1
MM_1 = t_1(2); % Minute digits of t_1
HH_2 = t_2(1); % Hour digits of t_2
MM_2 = t_2(2); % Minute digits of t_2
time_datenums = HH_1/24+MM_1/1440:1/1440:HH_2/24+MM_2/1440; % Array of datenums.
plot(time_datenums, power); % Plot data.
datetick('x', 'HH:MM'); % Set 'HH:MM' datetick format for the x axis.
This is the output:
I would use datenums:
Millis = [60000 120000 180000 240000 360000];
Power = [ 12 14 12 13 14 ];
d = [2017 05 01 08 00 00]; %starting point (y,m,d,h,m,s)
d = repmat(d,[length(Millis),1]);
d(:,6)=Millis/1000; %add them as seconds
D=datenum(d); %convert to datenums
plot(D,Power) %plot
datetick('x','HH:MM') %set the x-axis to datenums with HH:MM as format
an even shorter approach would be: (thanks to codeaviator for the idea)
Millis = [60000 120000 180000 240000 360000];
Power = [ 12 14 12 13 14 ];
D = 8/24+Millis/86400000; %24h / day, 86400000ms / day
plot(D,Power) %plot
datetick('x','HH:MM') %set the x-axis to datenums with HH:MM as format
I guess, there is an easier way using datetick and datenum, but I couldn't figure it out. This should solve your problem for now:
Millis=6e4:6e4:6e6;
power=randi([5 15],1,numel(Millis));
hours=floor(Millis/(6e4*60))+8; minutes=mod(Millis,(6e4*60))/6e4; % Calculate the hours and minutes of your Millisecond vector.
plot(Millis,power)
xlabels=arrayfun(#(x,y) sprintf('%d:%d',x,y),hours,minutes,'UniformOutput',0); % Create time-strings of the format HH:MM for your XTickLabels
tickDist=10; % define how often you want your XTicks (e.g. 1 if you want the ticks every minute)
set(gca,'XTick',Millis(tickDist:tickDist:end),'XTickLabel',xlabels(tickDist:tickDist:end))
I have a data set looks like this:
'2014-01-07 22:20:00' [0.0016]
'2014-01-07 22:25:00' [0.0013]
'2014-01-07 22:30:00' [0.0017]
'2014-01-07 22:35:00' [0.0020]
'2014-01-07 22:40:00' [0.0019]
'2014-01-07 22:45:00' [0.0022]
'2014-01-07 22:50:00' [0.0019]
'2014-01-07 22:55:00' [0.0019]
'2014-01-07 23:00:00' [0.0021]
'2014-01-07 23:05:00' [0.0021]
'2014-01-07 23:10:00' [0.0026]
First column is the time stamp recording data everything 5 min, second column is return.
For each day, I want to calculate sum of squared 5 min bar returns. Here I define a day as from 5:00 pm - 5:00 pm. ( So date 2014-01-07 is from 2014-01-06 17:00 to 2014-01-07 17:00 ). So for each day, I would sum squared returns from 5:00 pm - 5:00 pm. Output will be something like:
'2014-01-07' [0.046]
'2014-01-08' [0.033]
How should I do this?
Here is alternative solution
Just defining some randome data
t1 = datetime('2016-05-31 00:00:00','InputFormat','yyyy-MM-dd HH:mm:ss ');
t2 = datetime('2016-06-05 00:00:00','InputFormat','yyyy-MM-dd HH:mm:ss ');
Samples = 288; %because your sampling time is 5 mins
t = (t1:1/Samples:t2).';
X = rand(1,length(t));
First we find the sample which has the given criteria (Can be anything, In your case it was 00:05:00)
n = find(t.Hour >= 5,1,'first')
b = n;
Find the total number of days after the given sample
totaldays = length(find(diff(t.Day)))
and square and accumulate the 'return'for each day
for i = 1:totaldays - 1
sum_acc(i) = sum(X(b:b + (Samples - 1)).^2);
b = b + Samples;
end
This is just for visualization of the data
Dates = datetime(datestr(bsxfun(#plus ,datenum(t(n)) , 0:totaldays - 2)),'Format','yyyy-MM-dd')
table(Dates,sum_acc.','VariableNames',{'Date' 'Sum'})
Date Sum
__________ ______
2016-05-31 93.898
2016-06-01 90.164
2016-06-02 90.039
2016-06-03 91.676
I admit that your dates are in a cell and your values in a vector.
So for example you have:
date = {'2014-01-07 16:20:00','2014-01-07 22:25:00','2014-01-08 16:20:00','2014-01-08 22:25:00'};
value = [1 2 3 4];
You can find the sum for each date with:
%Creation of an index that separate each "day".
[~,~,ind] = unique(floor(cellfun(#datenum,date)+datenum(0,0,0,7,0,0))) %datenum(0,0,0,7,0,0) correspond to the offset
for i = 1:length(unique(ind))
sumdate(i) = sum(number(ind==i).^2)
end
And you can find the corresponding day of each sum with
datesum = cellstr(datestr(unique(floor(cellfun(#datenum,date)+datenum(0,0,0,7,0,0)))))
Hello this question might be easy but i am struggling to get average wind directions for 1 year. I need hourly averages to compare with concentration measurements. My wind measurements are every minute in degree. So my idea was to use the histc function in matlab to get the most common winddirection within the hour. this works for 1 h but how do i create a loop which gives me hourly values for a year.
here is the code
wdd=winddirections in degree(vectorsize e.g for a year 525600)
binranges = [0:10:360];
[bincounts,ind] = histc(wdd(1:60),binranges);
[num idx] = max(bincounts(:));
wd_out=binranges(idx);
kind regards matthias
How about this one -
binranges = [0:10:360]
[bincounts,ind] = histc(reshape(wdd,60,[]),binranges)
[nums idxs] = max(bincounts)
wd_out=binranges(idxs)
What I would do is:
wdd_phour=reshape(wdd,60,525600/60); % get a matrix of size 60(min) X hours per year
mean_phour=mean(wdd_phour,1); % compute the average of each 60 mins for every our in a year
I need some help related to plots in MATLAB.
I want to plot my data with respect to clock time on x-axis. I have an occupancy information data for every 15 minutes interval. I want to plot it against time. How can i do it? The problem is with the x-axis, how can i handle time and uniform intervals e.g data is of the form
data=[1 0 0 0 0 1 1 1 1 0 0 0 .............]
value of time is from 9 AM to 9 PM and the interval is 15 minutes
How can i set the intervals on the x-axis?
Thank you
The following code solves the problem. you enter Integer values for starting hour and minute, the ending time and the time steps between the measurements. Further enter/change the steps_x value. This shows how many time values are skipped on the x-axis. 7=skip6 values. Below the for-loop is my y-data. I just used random-function.
The resulting x-axis is a cell-array. This could be a problem for some applications. Further I used some 'unneccessary' variables. These i used for verifing my code. I didn't change it, because i thought that it would be easier to understand that way.
The biggest problem of my so
clc; clear all; close all;
%%//Variable declaration
start_hour = 9; %in hours
start_min = 5; %//in minutes
steps_min = 10; %//in minutes
end_hour = 21.0; %//in hours
end_min= 0; %//in minutes
steps_x = 7; %//how many times are displayed on the axis, doesn't change data
%%// code for computing internal values, steps and transforming to am/pm
%//changes the entries above to hour display(9.75=9h45min)
start_time= (start_hour+start_min/60);
%//changes the entries above to hour display(9.75=9h45min)
end_time=(end_hour+end_min/60);
%//changes steps to hour
steps_hour= steps_min/60;
%//array of hours
mytest_timeline = start_time:steps_hour:end_time;
%//array of minutes(copied and modified from #natan)
mytest_minutes = mod((0:steps_min:(steps_min*(length(mytest_timeline)-1)))+start_min,60);
%//cell array for am/pm display
mytest_timeline_ampm = num2cell(mytest_timeline);
%//if hour is smaller 12 write am otherwise pm
for k=1:length(mytest_timeline);
if mytest_timeline(k) < 12
mytest_ampm = {'am'};
%//converting the down rounded hour to str
helper_hour=num2str(mod(floor(mytest_timeline(k)),12));
%//converting the minute to str and giving it 2 digits eg. 05 for 5min
helper_minute = num2str(mytest_minutes(k),'%02d');
%//joining strings
mytest_timeline_ampm(k)= strcat(helper_hour,{'.'}, helper_minute, mytest_ampm);
%//same as for am just for pm
else
mytest_ampm = {'pm'};
helper_hour=num2str(mod(floor(mytest_timeline(k)),12));
helper_minute = num2str(mytest_minutes(k),'%02d');
mytest_timeline_ampm(k)= strcat(helper_hour,{'.'}, helper_minute, mytest_ampm);
end
end
%%// generated y data so that i could test the code
mytest_y = rand(size(mytest_timeline));
%%// changing display
%//x-coordinates(for displaying x,y)
mytest_x= 1:length(mytest_timeline);
%//x-axis label
mytest_x_axis = 1:steps_x:length(mytest_timeline);
%//plots the data mytest_y in uniform distances (mytest_x)
plot(mytest_x, mytest_y, 'b')
%//changes the x-label accordingly to mytest_x_axis to the am/pm timeline
set(gca, 'XTick',mytest_x_axis, 'XTickLabel',mytest_timeline_ampm(mytest_x_axis))