I'm using the ios-charts library and I have a LineChart View that has x values that are dates from every weekday of this year. On the y-axis I have values between 0 and 25.
I would like to zoom in on different intervals on the LineChart View.
For example only show Data for week X one time and later change to show data for three months, etc etc.
I did not find anything in the documentation on how to do this. I used the "zoom" function with out any success.
(Example : Zoom and show the last 20 days on the x axis or zoom and show the last three months)
Has someone does this before?
It's a tough question and very advanced control. I guess you need to read carefully about the code, focusing on moveViewToX, and the logic and functions in ChartTransformer. Combining some tricks and calculations, you may find a way to fine-grainedly controll what you want to display.
Also, there is a property:
/// the maximum number of entried to which values will be drawn
internal var _maxVisibleValueCount = 100
may also help you.
Related
In Vaadin 14.6.1, I tried to create a Vaadin heatmap foollowing the documentation / example from here.
However, I encountered a few problems/questions, listed in descending order of importance below:
The heatmap supported 30 rows by 30 columns; but when I tried 40 rows by 40 columns, the entire heatmap showed a single color (blue in my case).
Is it possible to manually set the minimum numeric value and maximum numeric value for the color scheme. This way, if I plot my data one day and it has values in the range of 0 to 1, but on another dataset from another day, the numeric values range from between 0 and 0.5, the color scheme range won't automatically change (to being between 0 and 0.5) and confuse the user.
In the documentation, it has the following methods listed, but they do not seem to exist in Vaadin 14.6.1
plotOptions.setBorderColor(SolidColor.WHITE);
plotOptions.setBorderWidth(2);
When I hover over the datapoints, is there a way that the tooltip can only show the numeric value (and not the x, y coordinate or the series name etc.?)
Is there any limit to the number of datapoints? I'm hoping that if #1 above is resolved that I can plot a 100 by 100 (ie 10,000) point heatmap.
If I plot 100by100, there will be many labels on the x and y axis. In my case, the x and y axis are actually numerical, so I did what the documentation suggested and just placed category labels in the xaxis and yaxis spots. However, is there any way to only display every "nth" label, so that the x-axis and y-axis is not so crowded? (This would essentially mimic what Vaadin does for normal line charts' xaxis and yaxis).
I'm not that experienced with Vaadin Chart, but these are the questions that I can comment on:
(1) With 40x40 items you go over the threshold of 1000 in which the Chart switches into "turbo" mode for performance reasons. This seems to not be compatible with the heatmap series. You can disable turbo mode by setting plotOptions.setTurboThreshold(0);
(2) Unfortunately the ColorAxis doesn't support this, it only has an API for min and max color. Definitely a valid use-case though, and it seems to be supported by the Highcharts library that the Vaadin Chart uses under the hood. You should consider opening a feature request for this in the Github repo.
(3) This seems to be a documentation issue. The methods are available in later Vaadin platform versions, but not in 14.6.
(5) In theory not, but in practice there will be a huge performance hit in the browser due to the excessive amount of DOM elements (quick test of 100x100 froze the browser for 10s). I'm afraid the component isn't really made for such extreme use-cases. In this case it might be better to utilize a low-level JS drawing library using the canvas, or draw an image on the server-side and display that in the browser. Maybe you can also consider modifying your use-case so that you only display one slice of your data and allow the user to switch between slices.
I am a quite new to mql4 coding. I would like to know how I write an indicator that does the following, based on the image below:
Draw a rectangle over the current day hour chart that covers the highest and lowest price points of the first 6 hours (candles)
Draw two horizontal lines along the highest and lowest points found 1.
Please note that 1. and 2. should be based strictly on the hourly period and shouldn't vary with the selected period.
I believe I'm suppose to be using ObjectCreate() with OBJ_RECTANGLE and OBJ_HLINE but the whole concept is quite new to me. I would really appreciate some assistance.
I want to use the Highcharts StockChart library to make a chart. Here's more info on the chart I need to create:
The type of the chart is datetime
The data is being updated on every minute (it's data from stocks), so the chart is being constantly updated.
The data of the chart is from 9:00am to 11:40am and then from 12:35pm to 3:00pm (there's a lunch break).
The data is being shown with bars in an interval of 5 minutes (data is received for every 5 minutes except for the lunch break).
The bars will start to be drawn from left to right as the data is received.
The bars width needs to be the same size regardless of how many data is being shown on the chart.
The labels of x axis of the chart need to be always the same and on the same position (from 9:00am to 3:00pm every hour) even when there's missing data (a line must be drawn on the x axis).
So, I'm using the max property set to that day at 3:00pm on the x axis of the chart. With this, I can:
Have the bars width to be the same
Have the x axis be drawn regardless of the missing data on the same interval (until 3pm).
Everything works ok until the lunch break (11:40am). However, when receiving data for 12:35pm (after lunch break), the chart will ignore the max property and the last line of the x axis that is drawn is until 1pm (this line needs to be drawn until 3pm). I assume that this is because until 11:40am all the data for 5 minutes is present, so the chart understands the interval on which the data needs to be drawn and also can draw the x axis lines on the same interval. But as soon as there's a gap on the data, the chart doesn't know anymore if data will keep coming in an interval of 5 minutes, so will just take into consideration all the data that has received until now, ignoring the max property.
I have tried different options in order to solve the issue:
I used ordinal property set to false. With this, I can solve the issue of the missing x axis labels until 3pm, but the issue is that the lunch break will have a gap on the chart. I need to merge the lunch break and having the x axis labels drawn until 3pm.
I tried to use the tickInterval property and was able to set the interval of the x axis but only for the data that is being drawn. However, the x axis label it still until 1pm and needs to be until 3pm.
I tried to use the breaks property for the lunch break while using the ordinal property set to false but didn't work. Also, the chart needs to be merged on the lunch break; using this property will create a gap on purpose, so this property won't help me to fix this issue.
So, I noticed that the interval is being changed correctly where there's data, but the lines are not being drawn where there's no data on the x axis (only until 1pm and not until 3pm). And if I use the ordinal property, it will show all the x axis lines for the missing data, but need to hide the gap for the lunch break.
Any help with this is appreciated =)
UPDATE:
I noticed that when there's still no data, if using v1.3.1 of highcharts (the one I'm currently using), the x axis lines are being drawn correctly until 3pm, but if using the latest version this doesn't happen. It seems that the max property is being ignored for the latest version.
Including the links of jsfiddle for my code on the comments (since stackoverflow doesn't allow me to post many links because don't have enough reputation).
I was able to achieve what I wanted. In the end what I did was to create null data to fill this gap for the lunch break. Also, I created null data for the remaining data until 3pm, that way the x axis lines were drawn properly: https://jsfiddle.net/K4Cj6/201/:
[1504528800000,null,null,null,null]
Thanks anyway guys =)
So I am using the Charts framework (formerly ios-charts) for a couple of charts.
One of them in a bar chart where the y-axis is duration in seconds - that I then convert into readable minute:second notation with a formatter.
But the selected interval of labels bugs me a little. I would like to control them so they are only shown at intervals that makes sense for this - like say every half or full minute. But I can't seem to find a way to do that for that axis. Only the x-axis seems to have options for that?
So am I missing something here? Or it is not in the framework?
Whoops. Never mind. I found the 'granularity' property on the axis right after asking. And it seems to do what I need.
I am using a Highcharts Stock graph to show a percentage with respect to time.
http://jsfiddle.net/michaelchart/yYmPR/1/
At certain zoom levels (in this case, when zooming to a timespan of between about 6 and 12 years) the plot strangely turns from a line to sporadic points.
Any ideas as to why this might be? Or is it a bug with Highstock?
You can see an example of a working Highstock graph here http://www.highcharts.com/stock/demo/basic-line.
After posting on the Highstock forum and consequently having an issue posted on github, I found that it was because of the default value of the gapSize option. According to the docs;
gapSize : Number
Defines when to display a gap in the graph. A gap size of 5 means that if the distance between two points is greater than five times that of the two closest points, the graph will be broken.
In practice, this option is most often used to visualize gaps in time series. In a stock chart, intraday data is available for daytime hours, while gaps will appear in nights and weekends.
Defaults to 5.
Setting gapSize to null fixes the problem.
In my particular case, the reason of this problem was bad data output.
Within "series" property, within the "data" array there was a "false" value.
Example:
series : {
"type":"column",
"name":"Test",
"data":[541,784,false,251,353]
}
Corrected the problem in the backend so "false" was interpreted as 0, and everything works now.