I'm trying to draw a temperature graph using iso-charts where the x axis data would be set from a server timestamp but the labels would be readable text.
For instance the graph x-axis label would start at Monday 00:00 and end Tuesday 12pm but the LineChartDataSet would be a collection of temperature (y-axis) and timestamps for the x
To display the timestamp I have a custom valueFormatter set as follow (which works great)
lineChartView.xAxis.valueFormatter = timestampXAxisFormatter() //converts timestamp to Date string
My question: The LineChartDataSet seems to be indexed based which is causing some trouble: if I have 4 data points such as (9am, 10), (9:15am, 11), (12pm, 15), (1pm, 16) the 4 points are set in the chart at regular intervals (I was expecting 2 points to be on the left side of the graph and then last 2 points on the right side) - Is there a way to have a data set that is based on the x value instead of the index?
I saw ChartData has an init that takes an array of NSObjects but then it converts it to Strings...Thanks in advance for any suggestions you may have!
There is no good way to solve it, as you figured out the x axis is index based.
You have two options:
insert many x values between each real x value, like between 9:00 and 9:15, you manually insert 9:01, 9:02, ..., 9:14, but don't add any entry at these values, just ignore it and continue. ios-charts will skip if no entry found and go to next. This will works fine, if you don't have a large number of values to insert. I tried ~1000 values, the performance is acceptable.
you create your own chart, using two y axis, one as x axis and one as y axis, so the distances to 0 point are calculated by value. However this requires you understand the ios-chart logic deeply. If you succeed, you are more than welcome to file a PR.
Related
I have half-hourly time series data; 48 data points in a day. The total time period starts from 4/6/2018 (i.e day/month/year) to 2/12/2018. I want to create a time series object. I am using ts function.
However, I am unable to define the frequency. As I know, frequency=1 for yearly data, but unable to define in my half-hourly data. How to solve this problem using ts object or there is any other way to do it?
After creating a time series object (i.e. date column), I want to plot it with the corresponding data series.
How to plot my result (in R object) on Y-axis and time period on the X-axis?
R <- function(x){
return(FDWhittle(x, method="discrete", sdf.method="multitaper"))
}
plot(R[,i],type="l",col = "Black", xlab="Time",
ylab="Return",main=names(R)[,i])
When I am plotting by using the above code, the results in the object "R" is coming on the Y-axis, and some values like (100, 200, 300--------) are coming on the X-axis. I want to get the time period on my X axis, but unable to define the intra-day date column having 48 data points in a day.
I have daily time series data and I want to calculate 5-day averages of that data while also retrieving the corresponding start date for each of the 5-day averages. For example:
x = [732099 732100 732101 732102 732103 732104 732105 732106 732107 732108];
y= [1 5 3 4 6 2 3 5 6 8];
Where x and y are actually size 92x1.
Firstly, how do I compute the 5-day mean when this time series data is not divisible by 5? Ultimately, I want to compute the 'jumping mean', where the average is not computed continuously (e.g., June 1-5, June 6-10, and so on).
I've tried doing the following:
Pentad_avg = mean(reshape(y(1:90),5,[]))'; %manually adjusted to be divisible by 5
Pentad_dt = x(1:5:90); %select every 5th day for time
However, Pentad_dt gives me dates 01-Jun-2004 and 06-Jun-2004 as output. And, that brings me to my second point.
I am looking to find 5-day averages for x and y that correspond to 5-day averages of another time series. This second time series has 5-day averaged data starting from 15-Jun-2004 until 29-Aug-2004 (instead of starting at 01-Jun-2004). Ultimately, how do I align the dates and 5-day averages between these two time series?
Synchronization between two time series can be accomplished using the timeseries object. Placing your data into an object allows Matlab to intelligently process it. The most useful thing is adds for your usage is the synchronize method.
You'll want to make sure to properly set the time vector on each of the timeseries objects.
An example of what this might look like is as follows:
ts1 = timeseries(y,datestr(x));
ts2 = timeseries(OtherData,OtherTimes);
[ts1 ts2] = synchronize(ts1,ts2,'Uniform','Interval',5);
This should return to you each timeseries aligned to be with the same times. You could also specify a specific time vector to align a timeseries to using the resample method.
I'm facing problem in getting the max % and min % from a table containing % difference values.
Year-----A----------B---------C---------D---------Max %----Max Type----Min %----Min Type
2012
2013---4.30%---4.42%---4.34%---4.38%----4.42%---------B-----------4.30%---------A
The table above shows the % difference in sales from previous year. Thus 2012 shows no % (because there's no 2011). I used table calculation to compute the % difference, i.e. "Percent Difference From", compute using "Table (Down)" and "Previous".
The last four columns are what I'm having trouble doing. I want to get the max % and min % and also the corresponding types. I'm not trying to add the four columns to the existing table, but to get the correct results, as my ultimate goal is to display that results on the dashboard, i.e. on my dashboard, I want to display the highest % and its corresponding type; similarly the lowest % and its corresponding type. For example: on my dashboard, I want to display:
Highest % and type: 4.42% B
Lowest % and type: 4.30% A
So, I need to have the correct formulas to get the max % and min % and their types. These are what I did:
I tried to use WINDOW_MAX and WINDOW_MIN to display the max % and min % on the table but got funky wrong results.
1) I first get the formula in calculating the % difference from the "Customize" button from "Edit Table Calculation" window of SUM([Sales]): (ZN(SUM([Sales])) - LOOKUP(ZN(SUM([Sales])), -1)) / ABS(LOOKUP(ZN(SUM([Sales])), -1))
Then I created a calculated field of the above formula. I named the calculated field "Percent-Diff".
2) I created another calculated filed (named "Max % Difference") using the formula: WINDOW_MAX([Percent-Diff]). But it shows strange results. See image below. I don't know why it gives me 2.78% and 2.91% for 2012 and 2013 respectively. It should be 0% and 4.42% for 2012 and 2013 respectively. Something is not correct.
If it is just SUM([Sales]) instead of % difference, then I get the correct result of showing the max sales using the formula WINDOW_MAX(SUM([Sales])).
3) Also I don't know how to get the corresponding type. I tried using the formula: IF [Max % Difference] = [Percent-Diff] THEN ATTR([Product Type]). But it returns:
NULL
B
I'm not sure if the formula is correct. It looks correct on the result (i.e. "B" is correct), except that it also shows a NULL value which I don't know why. I think it's because I didn't include the ELSE part in my IF formula? But why the NULL value is shown as the first value? I want the formula to return just one value, "B". So, how to only just show "B"?
I've posted twice the problem in tableau forum, but as of now, nobody has answered my problem. I believe that my formulas are incorrect. So, if anyone here can correct the formulas to get the max % and min % from % difference values and also to get the corresponding type, then it'd be very much appreciated. Thanks a million!
It's hard to tell not knowing how your database looks like (as you didn't explicitly presented it, but I can try to infer based on the clues you left on your post). But I could reproduce something like you said using the Sample - Coffee Chain Database, and it worked out well, calculated yoy sales increase by product and then window_max of that.
What you're probably missing is the partitioning. I suggest avoiding using Table or Pane to create the partitions in more complex situations (as it will work only in that specific arrangement of fields), but rather use the dimensions to partition it.
So, your [Percent-Diff] field should be compute using [Date], and your [Max % Difference] should be compute using [Product Type]. IMPORTANT, for [Max % Difference], when you go to Edit Table Calculation, you'll have to choose the Compute using for [Percent-Diff] as well (you can choose on the top of the window)
Your formula to find which type is the max (or min) is also correct (and should only respect the partitions). Nevertheless, it is very hard to have the exact output you're expecting.
What I would do is to create 2 spreadsheets (and later combine them in a dashboard).
The 1st would be what you already got (Each product [Percent-Diff]
The second one I would change your formula (3) to just [Max % Difference] = [Percent-Diff], and use it as filter (filtering only true). I would drag both Date and Product to the sheet (you choose if you want it on columns, rows, or just detail) so I can use them to partition the table. And drag [Max % Difference] to be visualized.
That way you'll only see the product that is the max, and how much is that max.
Hope it helps
I have been searching various forums for hours but it seems impossible to do a thing in Matlab that's automatic in excel...
I used uiimport to import an xls file with into two arrays (? total newbie), one containing dates for my x-axis and the other the values I want to plot.
I have 180 values. The dates are three dates per month, more or less ranging from May 2008 until now, end of March.
Using
plot(mynumbers)
set(gca,'XTickLabel',dates)
only puts dates for May 2008 on my x-axis!
where did all the other dates go?
Instead using
plot(mynumbers)
set(gca,'XTick',mynumbers,'XTickLabel',dates)
gives error message
"??? Error using ==> set
Values must be monotonically increasing."
Please help!
where did all the other dates go?
The answer to your first question is that MATLAB only uses the first N number of strings corresponding to the default N number of tick marks on the x axis.
"??? Error using ==> set Values must be monotonically increasing."
The error is telling you that your date ticks must be evenly spaced. Instead of using dates corresponding to your actual data points, you could grab the x tick values that MATLAB automatically assigned to your graph, translate them to text, and then reassign the dates as x tick labels, like so:
% generate example unevenly spaced date vector
time = [now,now+1,now+25,now+28.5,now+36,now+40,now+51,now+65];
% generate random data points
data = rand(size(time));
% plot time vs data, storing the axes handle in the process
figure;
axH = axes;
plot(axH,time,data)
% get the x-axis tick locations
ticLoc = get(axH,'XTick');
% format tick labels (substitute any date format you wish)
ticLab = cellfun(#(x) datestr(x,'mm/dd'),num2cell(ticLoc),'UniformOutput',false);
% apply tick labels
set(axH,'XTickLabel',ticLab)
MATLAB's built-in function datetick also performs similarly.
However, if you zoom afterwards, you won't have accurate tick labels. So you may want to use datetick2 on the File Exchange.
If you're having trouble converting a cell array of dates from Excel into a numeric array, use:
dateNumeric = cell2mat(cellfun(#datenum,dateStrings,'UniformOutput',false));
try set (gca,'XTickLabel',num2str(dates))
i'm trying to draw a Graph with a user-friendly timeline having every day/week (to be decided by time range) as a label at x-axis. However, the datasource values are given on another basis - there might be 10 entries one day and the eleventh comes in a month.
See the photoshop image:
With the latest Core Plot drop I cannot find a way to do it, need your help.
Regards,
user792677.
The scatter plot asks the datasource for x-y pairs of data. There is no requirement that either value follow some sort of sequence or regular pattern. Other plot types work similarly, although the names and number of data fields can vary.
In your example, return 4 from the -numberOfRecordsForPlot: method. Return the following values from the -numberForPlot:field:recordIndex: method. The table assumes your y-values are calculated by a function f(x), but they can of course come from any source. Use the field parameter to determine whether the plot is asking for the x- or y- value.
Index X-Value Y-Value
0 1 f(1)
1 3 f(3)
2 9 f(9)
3 10 f(10)