Csaba, have the same wish for extracting the simple linear fit equation from trendline (top chart), and recast trendline overlay on histogram (bottom chart).
Q: any update or alternate pathway to accomplish that using Google Chart? On Saturday, September 30, 2017 at 10:41:11 PM UTC-5 Csaba Toth wrote: > Also for reference: > https://github.com/google/google-visualization-issues/issues/2561 > > > On Friday, January 22, 2016 at 11:04:02 AM UTC-8, Sergey wrote: > >> Hi Nick, >> >> Thanks for your message. >> >> We currently don't have any way of exporting trendline data. The entire >> purpose of this thread was to figure out what data people actually wanted. >> However, it seemed to me that the thread didn't reach consensus, and some >> of the posts were just flatout off-topic. >> >> So to answer your questions, you currently cannot extract the trendline >> data from a chart. If you need this today and are unwilling to wait for us >> to implement the trendline retrieval API (which could take a while), you >> would have to implement your own linear regression >> <https://en.wikipedia.org/wiki/Linear_regression>, and compute the >> trendline yourself. >> >> As for your second question, we have not given any thought to piecewise >> trendlines. We will consider this feature for inclusion in the API when we >> start work on implementing multiple trendlines for the same series. >> >> On Fri, Jan 22, 2016 at 11:07 AM <[email protected]> wrote: >> > Hi Sergey, >>> I wanted to resuscitate this thread because I had a couple of questions. >>> >>> Firstly, what is the current official method for exporting trendline >>> data? I know that your API stores the information because it appears in the >>> trendline tooltip. Suppose I want to get that information in an array? Or >>> how would I go about generating a series of trendline data points that I >>> can plot separately? This is important to me in a current application where >>> I need to store scatter chart trendlines from mulitple datasets in their >>> own dataTable which I can use separately to generate line charts. >>> >>> The second question is whether you have given any thought to including >>> spline fitting functionality in your trendlines. Here the use scenario >>> might be that I want to use a cubic polynomial for data domain X: {0,10} >>> and a linear trendline for X>10, with a spline fit to join them together. >>> >>> All feedback appreciated. >>> >>> Nick >>> >>> >>> On Tuesday, October 28, 2014 at 6:33:35 PM UTC, Sergey wrote: >>>> >>>> Dearest Google Charts users, >>>> >>>> >>>> We have been working hard on improving charts, and now need your input. >>>> We are considering adding a few methods to our corecharts to help you get >>>> data about your trendlines, such as the r^2 value. However, we're not >>>> quite >>>> sure how you’ll want to use them. We know that we want a method to get the >>>> trendline r^2 value, and we think that getting an evaluator function for a >>>> trendline would be useful as well; but we also want to give you the >>>> ability >>>> to pull out the trendline expression. Here's where things get a bit blurry. >>>> >>>> >>>> We could do the simple thing, and simply create a method that returns >>>> the plaintext equation. This would allow you to show the equation >>>> elsewhere >>>> on the page. You might also parse it, but parsing can be hard, so we’ll >>>> provide some utilities to help with that. Some alternatives to mitigate >>>> this issue would be: >>>> >>>> - >>>> >>>> to return a JSON form an abstract syntax tree >>>> <http://en.wikipedia.org/wiki/Abstract_syntax_tree> of the >>>> equation, an example might be: >>>> - >>>> >>>> y = 2x + 1: {operation: '=', operands: ['y', {operation: '+', >>>> operands: [{operation: '*', operands: [2, 'x']}, 1]}]} >>>> - >>>> >>>> to return a Lisp/Scheme-like abstract syntax tree, using arrays and >>>> prefix notation. An example of that might be: >>>> - >>>> >>>> y = 2x + 1: ['=', 'y', ['+', [2, 'x'], 1]] >>>> - >>>> >>>> to return an array of coefficients, possibly with the type of the >>>> trendline: >>>> - >>>> >>>> 2x + 1: {type: 'linear', coefficients: [2, 1]} >>>> - >>>> >>>> exp(5x + 3): {type: 'exponential', coefficients: [5, 3]} >>>> >>>> >>>> We can also return an abstract syntax tree as well as a plaintext form, >>>> though that is getting a bit redundant. So, what are your thoughts here? >>>> Your opinions are most welcome. >>>> >>>> >>>> Happy Coding, >>>> >>>> Sergey and the rest of the Google Charts Team >>>> >>>> >>>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Google Visualization API" group. >>> >> To unsubscribe from this group and stop receiving emails from it, send an >>> email to [email protected]. >> >> >>> To post to this group, send email to [email protected]. >>> Visit this group at >>> https://groups.google.com/group/google-visualization-api. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/google-visualization-api/3d24532b-df2b-4894-a0dc-c6bf6e4db97e%40googlegroups.com >>> >>> <https://groups.google.com/d/msgid/google-visualization-api/3d24532b-df2b-4894-a0dc-c6bf6e4db97e%40googlegroups.com?utm_medium=email&utm_source=footer> >>> . >>> For more options, visit https://groups.google.com/d/optout. >>> >> -- >> >> *[image: unnamed.gif]• Sergey Grabkovsky• Software Engineer• Google, Inc• >> [email protected]* >> >> -- You received this message because you are subscribed to the Google Groups "Google Visualization API" group. 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