Mschart gridlines not starting from zero - mschart

In VS2010 VB I am using MSChart (.Net 4) and I have a FastLine chart with values from -2000 to 2000 for X axis and -20 to 20 on Y axis.
The interval for the gridlines in X axix is 250 and I need the gridlines to be "mirrored" from origin (i.e. -250, 250; -500, 500;...) but when I execute the applications always the first gridlines are -200, 50 and then -450, 300...
I tried using StartFromZero = True in the axes properties without success. Is there any way to force the gridlines to be symetric from the origin (zero) ?

Thank you for your comments.
I solved this issue by setting the IntervalOffset of the Axis. This offset represents the offset of the first gridline from left of the chart (in the case of X axix) . By calculating the displacement required (myChart.ChartAreas(0).AxisX.IntervalOffset = myChart.ChartAreas(0).AxisX.Maximum Mod yourIntervalValue) to reach 0 from left most value with the interval used, I was able to make the gridline in the middle of the chart to match the zero line.
I hope it helps others.

Related

Chart.js: Fixed horizontal location of vertical axis

How can I guarantee a fixed horizontal location for the vertical axis in terms of pixel from the edge of the screen? The photo shows how the axis location varies depending on number of digits in the scale labels. (I need the X in the photo to be constant so the plot will line up with other elements on the page.)
I've tried adjusting:
Options > layout > padding > left; and that shifts everything to the right but the location of the vertical axis still depends on the number of digits in the y-axis scale labels.
Options > scales > yAxes > ticks > padding; that changes the space between the label and the axis but it doesn't guarantee a location for the vertical axis.
(I'm using options > responsive = false.)
Maybe there's a better way, but this worked for me.
In the chart options I set: options > layout > padding > left to a default pixel amount that works for my situation when the scale label has only two digit number labels.
Then I set an ID for the yAxes so that I can access it later: options > scales > yAxes > id.
Then in my JavaScript, after the code that defines the chart, I added the following code which adjusts the left padding if the scale label has three digits (in my case I set it to 1):
var axis = myLineChart.scales.<id of my y axis>;
var max_tick_label = axis.ticks[0];
if (max_tick_label >= 100) {
myLineChart.options.layout.padding['left'] = 1;
myLineChart.update();
}

Google Charts - Color of gridlines for negative values on y-axis

I have a chart like this:
and I would like to change the color of Y-Axis grid lines below "0" so both -0.5 and -1.0 grid lines will become, for example, red.
Is it possible?
In your chart.draw/ options call, add:
vAxis:{viewWindow: {min: 0}}

Is there any way to add gridlines to a gRaphael line chart?

I have a line chart that I've created with gRaphael. It has axes and tick marks, but I'd like to have grid lines. Is there built-in way to achieve this or an add on library that can help me?
gRaphael does not have a built-in way to add grid lines, but it is pretty easy to draw them, either by editing the source code or manipulating your graph object after you create it.
I had found an extension called RaphAlytics and used its drawGrid() function in cases where I needed a bounding box with a grid.
You can adapt this function for any gRaphael graph as needed to draw gridlines. On a line chart, I needed to draw horizontal gridlines that were aligned with the left axis marks on a line chart, so I used the function as an example like this:
// Draw horizontal gridlines
for (var i = 0; i < g.axis[1].text.items.length; i++) {
r.path(['M', x, g.axis[1].text.items[i].attrs.y, 'H', w + x]).attr({
stroke : '#EEE'
}).toBack();
}
Here's a working fiddle to illustrate that example: http://jsfiddle.net/KM3BB/1/
I tried doing this yesterday. Short answer: gRaphaël can't do this for you with any linechart options nor axis options, you have to do-it-yourself with Raphaël.
Something like:
var r = Raphael("holder"), txtattr = { font: "12px sans-serif" };
r.path('M 15 200.5 L 310 200.5 M 15 180.5 L 310 200.5');
r.linechart(10, 10, 300, 220, x, [y, y2, y3]);
This means under my linechart draw a path which starts from 15,200.5 and draws a straight line to 310,200.5 moves to 15,180.5 and draws a line to 310,180.5. Don't ask me why but the .5 is important for getting the stroke to actually be 1px wide and solid black. Otherwise it seems to get aliased to 2px wide at 50% opacity. You have to calculate the exact placement in regards to your linechart yourself.
You can also play with the path function in the playground by changing r to paper.
You might also consider looking at Google Chart Tools if your looking for things like defining the exact range of the axis (as opposed to just the min and max of the input).

SetViewBox moving the paper

I am using the setViewBox() function in Raphael 2. The width and height is multiplied by a value like (1.2, 1.3 ...). This changes the magnification/ zooming properly but the x and y which I have given as 0,0 makes the paper display its contents after some offset. If i modify the x and y to some positive value after the rendering( using firebug!!) then the top left of the paper moves back and above to its right position. I want to know how will the value be calculated. I have no idea about how the x,y affect the viewbox. If anybody can give me any pointers for this it will be a real help.
I have tried giving the difference between the width/ height divided by 2. Also I must mention that I am not rendering an image but various raphael shapes e.g. rects, paths text etc. in my paper.
Looking forward to some help!
Kavita
this is an example showing how to calculate the setViewBox values, I included jquery (to get my SVG cocntainer X and Y : $("#"+map_name).offset().left and $("#"+map_name).offset().top) and after that I calculated how much zoom I need :
var original_width = 777;
var original_height = 667;
var zoom_width = map_width*100/original_width/100;
var zoom_height = map_height*100/original_height/100;
if(zoom_width<=zoom_height)
zoom = zoom_width;
else
zoom = zoom_height;
rsr.setViewBox($("#"+map_name).offset().left, $("#"+map_name).offset().top, (map_width/zoom), (map_height/zoom));
did you put the center of your scaling to 0,0 like:
element.scale(1.2,1.2,0,0);
this can scale your element without moving the coordinates of the top left corner.

google charts api : wrong axis with LXY chart?

I'm trying to display some very simple data using Google Charts API.
My data are a serie of X,Y points:
(1,44) (2,46) (3,46) (4,43) (5,46) and (6,44).
X-axis : from 0 to 300, step 50
Y-axis : from 1 to 50, step 5
I should end up with a line almost in the top, to the left, of the chart (43-46 are near 50).
But here is what I get:
URL = http://chart.apis.google.com/chart?cht=lxy&chs=500x300&chd=t:1,2,3,4,5,6|44,46,46,43,46,44&chxt=x,y&chxr=0,0,300,50|1,0,50,5
If I change Y-axis, 1 to 100 (instead of 50), it's ok...
URL = http://chart.apis.google.com/chart?cht=lxy&chs=500x300&chd=t:1,2,3,4,5,6|44,46,46,43,46,44&chxt=x,y&chxr=0,0,300,50|1,0,100,5
I'm probably mistaking, but I can't find what is wrong.
If you add data scale the chart does show correctly.
http://chart.apis.google.com/chart?cht=lxy&chs=500x300&chd=t:1,2,3,4,5,6|44,46,46,43,46,44&chxt=x,y&chxr=0,0,300,50|1,0,50,5&chds=0,300,0,50