Skip to main content

data acquisition - Excel DDE Link: reading and writing in real time


I'm wondering if it is possible to link Excel and Mathematica in real time, so that Mathematica can be used as a computing and "storage" tool. Suppose I have an Excel spreadsheet with an active DDE link:


enter image description here


I would like to know if it is possible for Mathematica to communicate with Excel in real time and store every cell update in Excel. I know there is a package called ExcelLink, with several functions to link Mathematica and Excel. So, if I use, for instance ExcelRead["A2"] I get the correct value



19.36




However, it is not dynamic! I can get dynamic values by using


a=Dynamic[Refresh[ExcelRead["A2"], UpdateInterval -> 0]]
b=Dynamic[Refresh[ExcelRead["B2"], UpdateInterval -> 0]]

However, when I try to add a+b I get



19.36+28.56



And, worse, If I use



Dynamic[a+b, UpdateInterval -> 0]

I get



19.36+28.56



So, here arises my first problem: although Mathematica reads the values in real time from Excel, I'm not able to perform any calculation with them. Is there any way to do it?


My second problem is: how can I write dynamically the values I'm getting from the DDE Link inside Excel itself? I need to write every updated value in Excel in a sequence like shown below


enter image description here



Answer




After some research I've found this partial solution:


Step 1: Open Excel (if you have it!)


Step 2: Open Excel Link


Needs["ExcelLink`"]

Step 3: If you don't have any DDE Link for Excel, simulate real time data using


Dynamic[Refresh[Excel["B1"] = RandomInteger[100], UpdateInterval -> 1]]

Step 4: Import back to Mathematica your simulated data


a = Dynamic[Refresh[ExcelRead["B1"], UpdateInterval -> 1]]


Step 5: Create a numberic list and set Dynamic[] to append sequential numbers to it every 1 second


numlist = {}; k = 1;
num = Dynamic[Refresh[AppendTo[numlist, k++];Last@numlist, UpdateInterval -> 1], TrackedSymbols -> {}]

Step 6: Create a string list (for cell values) and set Dynamic[] to append sequential values to it every 1 second


cellslist = {}; j = 1;
cell = Dynamic[Refresh[AppendTo[cellslist, "A" <> ToString[Last[numlist]]];Last@cellslist, UpdateInterval -> 1], TrackedSymbols -> {}]

Step 7: Store the values in Excel itself!!! (thanks to @rm-rf for the Setting tip!)



Dynamic[Refresh[Excel[Last@cellslist] = Setting@a, UpdateInterval -> 1]]

Result


enter image description here



This is a solution using UpdateInterval->1 . However, I would appreciate any solution with asynchronous reading and writing in real time.


Comments

Post a Comment

Popular posts from this blog

plotting - How to draw lines between specified dots on ListPlot?

I would like to create a plot where I have unconnected dots and some connected. So far, I have figured out how to draw the dots. My code is the following: ListPlot[{{1, 1}, {2, 2}, {3, 3}, {4, 4}, {1, 4}, {2, 5}, {3, 6}, {4, 7}, {1, 7}, {2, 8}, {3, 9}, {4, 10}, {1, 10}, {2, 11}, {3, 12}, {4,13}, {2.5, 7}}, Ticks -> {{1, 2, 3, 4}, None}, AxesStyle -> Thin, TicksStyle -> Directive[Black, Bold, 12], Mesh -> Full] I have thought using ListLinePlot command, but I don't know how to specify to the command to draw only selected lines between the dots. Do have any suggestions/hints on how to do that? Thank you. Answer One possibility would be to use Epilog with Line : ListPlot[ {{1, 1}, {2, 2}, {3, 3}, {4, 4}, {1, 4}, {2, 5}, {3, 6}, {4, 7}, {1, 7}, {2, 8}, {3, 9}, {4, 10}, {1, 10}, {2, 11}, {3, 12}, {4, 13}, {2.5, 7}}, Ticks -> {{1, 2, 3, 4}, None}, AxesStyle -> Thin, TicksStyle -> Directive[Black, Bold, 12], Mesh -> Full, Epilog -> { Line[ ...
Post a Comment
Read more

dynamic - How can I make a clickable ArrayPlot that returns input?

I would like to create a dynamic ArrayPlot so that the rectangles, when clicked, provide the input. Can I use ArrayPlot for this? Or is there something else I should have to use? Answer ArrayPlot is much more than just a simple array like Grid : it represents a ranged 2D dataset, and its visualization can be finetuned by options like DataReversed and DataRange . These features make it quite complicated to reproduce the same layout and order with Grid . Here I offer AnnotatedArrayPlot which comes in handy when your dataset is more than just a flat 2D array. The dynamic interface allows highlighting individual cells and possibly interacting with them. AnnotatedArrayPlot works the same way as ArrayPlot and accepts the same options plus Enabled , HighlightCoordinates , HighlightStyle and HighlightElementFunction . data = {{Missing["HasSomeMoreData"], GrayLevel[ 1], {RGBColor[0, 1, 1], RGBColor[0, 0, 1], GrayLevel[1]}, RGBColor[0, 1, 0]}, {GrayLevel[0], GrayLevel...
Post a Comment
Read more

list manipulation - Selecting multiple columns from a matrix?

Sample data: data = { {{2013, 1, 1}, 24.13, 167.67, 231.82}, {{2013, 1, 2}, 32.15, 170.92, 225.99}, {{2013, 1, 3}, 35.43, 172.68, 221.67}, {{2013, 1, 4}, 36.73, 173.05, 218.32}, {{2013, 1, 5}, 58.19, 165.96, 197.05}, {{2013, 1, 6}, 69.99, 163.50, 187.52}, {{2013, 1, 7}, 71.37, 154.21, 175.58}, {{2013, 1, 8}, 72.51, 149.66, 163.25}}; I want a DateListPlot with three graphs, so for a matrix formed by columns 1 and 2, one for columns 1 and 3, and 1 for columns 1 and 4. At the moment I'm using this code: data2 = Transpose[{data[[All, 1]], data[[All, 2]]}]; data3 = Transpose[{data[[All, 1]], data[[All, 3]]}]; data4 = Transpose[{data[[All, 1]], data[[All, 4]]}]; DateListPlot[{data2, data3, data4}, Joined -> True, Filling -> {3 -> {1}}] but I have a hunch that this can be done more efficiently. I don't like the Transpose s in particular. Any ideas? edit (for extra credit) What if I need to multiply the second column by 2, which in my solution is simp...
Post a Comment
Read more