Linear Plot on a Log axis

Hello,
what I want to do is quite unusual (I think) so I will explain the context :
I made a program which capture data off a spectrum analyser, correct these data with antenna correction, and use VIs "Limit Specification.vi" and "Limit Testing.vi" to interpolate my datas with a Pattern. The aim is to verify that the datas from the analyser don't get over the pattern.
Everything is then put in a Waveform Graph, with a Logarithm X Scale.
BUT the problem is that when I put X scale on "log" in graph properties, my Pattern representation is transformed in a Log-horrible-thing. I know it's working as intended, but my program isn't unusable because of this.
How can I do to make the interpolation "Linear" in a Log scale ? Is it possible using both limits VIs, or not ? I hope yes..
Here are some screenshot of the thing (can't join my VI, it's property of the company I work for (i'm in placement)).
Thanks for your future help !
Message Edité par JDlabview le 05-27-2010 10:19 AM
J.D.
French Labview beginner
N'oubliez pas de complimenter les bonnes réponses - Don't forget Kudos for good answers
Solved!
Go to Solution.

Thank you sooooo much Felix, you made my day !!!
I post the solution if someone needs it 
1- I transform my waveform points in log10 base :
2- Same with my pattern (limit) points :
3- I use the Limit specification and Limit testing VIs with these new X points (and dt=-1 because my waveform isn't linear anymore)
4-And finally, I use 10^x function and change my Waveform out of Limit Testing, in an XY graph :
If moderators find this post inconvenient because too big or useless, no worry to delete it.
Thanks to all of you LabView and NI experts to help beginners in their development
J.D.
French Labview beginner
N'oubliez pas de complimenter les bonnes réponses - Don't forget Kudos for good answers

Similar Messages

  • Bubble chart Log axis

    Hi,
    I am drawing a bubble chart with two types of axes: Linear and Log. The bubble points do not get plot correctly in case of Log Axis. Linear axis show fine though.
    Any clue why it might be showing wrong ?
    Thanks,
    Tanu

    I got the solution myself !!!
    I was using Flex 4 SDK which has this bug in LogAxis. I used Log Axis of Flex SDK 3.0 and it ran perfectly fine.:)
    Tanu

  • Log Axis Graph Question

    Does anyone know if it is possible to modify the the log axis
    to set arbitrary limits.
    By default the extents are 1,10,100,1000 etc. I want to
    create an audio test chart with lower limit of 20 Hz and upper
    limit of 20 kHz.

    I know this was a while ago now, but did you ever get anywhere with your search for a better Log axis? I'm looking for exactly the same thing.

  • Log axis

    Hello,
    I am a bit puzzled by the scaling of my log scale...
    Say the range is -.2 (or zero) to 17788.
    1) Changing the map mode to log I would have expected an error, according to the documentation:
    Use a logarithmic scale for the graph axis. The minimum axis value must be greater than zero.
    Obviously, it must not.
    2) Having the axis autoscaled, the smallest label is 18, with intermediate labels of 100, 1000, 10000, and the largest label is 17788.
    Why is the smallest label 18 and not 10, or 1, or 0.1??
    I have Auto Divisions but no Loose Fit.
    Thanks, Wolfgang
    Solved!
    Go to Solution.

    Hi Wolfgang,
    The reason it is being coerced to such a high value is because you have Loose Fit (ATTR_XLOOSE_FIT_AUTOSCALING) enabled for autoscaling and too high of a Loose Fit AutoScale Unit (ATTR_XLOOSE_FIT_AUTOSCALING_UNIT). The autoscaling unit is the log factor that the autoscaling will use for rounding. You probably have the autoscaling unit set to 2 which is the default. This means that it will round to the next higher for max and next lower for min value that is a factor of 100. This works great for a linear scale, but you can see an obvious problem with this design for log scales. By the very nature of the log scale, it does not make sense to round based on the same factor.
    The reason you are getting a min value of 18 is because the true min of the data is smaller than the autoscaling loose fit factor. And since it cannot use 0 as the min since it is an invalid value for log, it instead defaults to 1/1000 of the max.
    There are a few issues here with loose fit on a log scale, so I have filed a bug report that you can track with ID: 352509.
    In the meantime, I found that disabling loose fit allows the autoscale to work correctly even with negative data values. However, if you want to have a loose fit (i.e. you min and max on the scale have a buffer around the min and max of the data), then you will have to implement this yourself. You can use autoscaling when plotting data to automatically detect the max and min of the data, then switch to a fixed scale so that you can then add the buffer region to create a loose fit. Or you can leave autoscaling off and calculate the min and max values yourself.
    National Instruments
    Product Support Engineer

  • Plot values in X-Axis in 2D line graph

    Hi,
    I am using 2D line graph to plot graph but the graph is to be ploted based on date i.e i have a range to be ploted in X-Axis i.e Dates how to plot that please suggest now the values are automatically it is getting ploted
    This is query wht i am using
    SELECT
    pobj.name "Object Name",
    tas.name "Task Name",
    SUM (TCL.NUM_HOURS_DAY1+TCL.NUM_HOURS_DAY2+TCL.NUM_HOURS_DAY3+TCL.NUM_HOURS_DAY4+TCL.NUM_HOURS_DAY5+TCL.NUM_HOURS_DAY6+TCL.NUM_HOURS_DAY7) ) "Effort"
    FROM
    timecard_lines tcl,
    project_objects pobj,
    tasks tas,
    projects pro,
    timecard_headers thr,
    employees epl,
    object_task_estimate ote,
    TIMECARD_PERIODS TP
    WHERE
    pro.id = :P61_PROJECTS and
    tas.id = :P61_TASKS and
    TP.ID = THR.TPD_ID AND
    tcl.pobj_id = pobj.id AND
    tcl.tas_id = tas.id AND
    pro.id = pobj.pro_id AND
    thr.id = tcl.thr_id AND
    thr.emp_id = epl.id AND
    ote.tas_id = tas.id AND
    pobj.id = tcl.pobj_id
    and
    ote.pobj_id = pobj.id and
    pro.id in
    (SELECT pro.id
    FROM projects pro, employee_project_pairs
    epp, project_employee_roles per ,employees empl
    WHERE empl.id = epp.emp_id
    AND pro.id = epp.pro_id
    AND epp.project_role_id = per.id )
    group by pro.project_name,pobj.name,tas.name
    order by pobj.name

    Standard syntax on the Mac is Object, Action. The order is always Select an object (in this case, part of a spreadsheet), then perform an action on or with tat object (in this case, make a chart).
    The same syntax applies to Copy or Cut (and to Paste, althyough it's not as obvious there—the object is whatever is currently on the Clipboard).
    I don't think there is information on printing charts/graphs in the online help. A chart is a graphics object, and is printed as part of the document that contains it. Printing the spreadsheet should also print the chart, provided it is on a page that contains data (AppleWorks's default is to print only the rows and columns that contain data). If you want to print the chart without any of the data, drag the chart over the data to conceal it, and choose the Print options that do not show column or row headers and the cell grid. (These are probably in the AppleWorks options in your Print dialogue, but their position will depend on your print driver.)
    Placing the object (the chart) in another document provides an easier method of printing only the chart, and the method you used (dragging the chart from the spreadsheet to the second document is a common and acceptable one. Dragging an object from one document to another places a copy of the object on the second document, and leaves the original on the original document. This is true in general, not just for charts.
    In the case of a chart, the copy is a static object, while the original maintains its live connection to the underlying spreadsheet—changing a graphed value in the spreadsheet will change the graph to match the new value, but will not affect the copy in the second document.
    Regards,
    Barry

  • How to plot dates on X-axis in Numbers?

    Hey all, need help!
    Have a two-column data layout, with dates in first column and values in second.  For example,
    April 12, 2009 465
    July 16, 2009 329
    Sep 2, 2009 528
    Nov 21, 2009 503
    I'd like to plot this as a scatter plot and see dates on the x-axis (a la Excel).  Alas, all it shows are numeric equivalents on the x axis, in very large numbers.
    What's the trick or solution to this?
    (I have spent a good half hour rummaging the boards here and Googling to no avail.  I did discover the DUR2DAYS trick for doing a related graph in the spreadsheet... perhaps there's a formatting trick here, too.)

    BUMP!
    Anyone?

  • Plot Multi-XY:x-axis hosed

    Using the "Plot Multi-XY" (picture output). This has to be something simple I'm overlooking. I'm setting both my Y and X-axis to 0 digits of precision. Y axis behaves as expected, but you can see the X-axis problem in the screen shot below. Setting 1 digit of precision works fine.
    LabVIEW 8.5
    Message Edited by Bill@NGC on 07-11-2008 07:21 PM
    “A child of five could understand this. Send someone to fetch a child of five.”
    ― Groucho Marx
    Attachments:
    graphhosed.png ‏5 KB

    Here's the VI I was talking about.
    Ton
    Free Code Capture Tool! Version 2.1.3 with comments, web-upload, back-save and snippets!
    Nederlandse LabVIEW user groep www.lvug.nl
    My LabVIEW Ideas
    LabVIEW, programming like it should be!
    Attachments:
    RemoveFalseTicks.vi ‏28 KB

  • Log Axis value?

    Hello
    The X axis I think in the display panel logQ base Q, but the X axis value or the logQ this calculated value, for example: the requirement that correspond to the 1000 in the log1000 X axis,. Would you please tell me how to do? As shown in Fig.
    Thank you

    I'm not sure if I understood you correctly, but every single axis in a graph can have a log scale: you can set it this way:
    The result is as follows:
    If this is not your problem, can you rephrase your questio so that we can understood what you need?
    Proud to use LW/CVI from 3.1 on.
    My contributions to the Developer Zone Community
    If I have helped you, why not giving me a kudos?

  • Linear Encoder and Configure Logging

    Hi All,
    I am currently using a PCI-6280 M-series board with LV2010.
    I have a Linear Encoder in X4 mode connected to Counter 0 and I was wondering if it is possible to stream the values on the counter as it keeps track of the distance into a TDMS file using "DAQmx Configure Logging" .  I tried this using MAX to configure this, but it does not seem to work, so I'm just wondering if this is even possible as I couldn't seem to find anything online about doing this.
    Thanks,
    Lester
    Solved!
    Go to Solution.

    Hi Lester,
    My apologies, I tried it out on a different board. It can work with yours, too, though. There is an example of a buffered counter task that should allow you to log the data by adding in the Configure Logging VI like we did before.
    Open LabVIEW and go to Help >> Find Examples... it will open the Example Finder. In the Example Finder, expand the folders to get to Hardware Input and Output >> DAQmx >> Counter Measurements >> Count Digital Events >> Count Digital Events-Buffered-Countinuous-Ext Clk.vi
    Put the correct counter channel and PFI channel in the controls, and run the VI to see what it does. Then you can modify the block diagram to add the Configure Logging VI (the same way as before) and run the VI again. You will end up with a TDMS log saved at the path you wire into the Configure Logging VI.
    I hope that helps.
    Regards,
    Daniel H.
    Customer Education Product Support Engineer
    National Instruments
    Certified LabVIEW Developer

  • Xy scatter plot with 2 y axis how to?

    I am interested in an making an XY scatter plot with time points as
    the x axis, and with 2 different y axis.
    As I mentioned, the x axis
    will have the different time in min., that the data was collected, and
    the 1 y axis would contain a particular measurement of the sample, and
    the other (2nd) y axis would contain a different type of measurement
    of the same sample. The problem is that I can't see how to do a 2 y
    axis XY scatter plot.
    best regards
    Peter Valencic

    Hi Peter,
    This is one of the most requested features for the JFreeChart project. It hasn't been added yet, but it is very near the top of the to-do list.
    Regards,
    Dave Gilbert
    JFreeChart Project Leader
    P.S. For anyone who is interested in JFreeChart, the link is:
    http://www.object-refinery.com/jfreechart/index.html

  • Data being plotted in the wrong axis

    I am trying to make a simple line graph with 2 different groups plotted against time. In my table I've got time (first coloumn), group 1 (2nd column) and group 2 (3rd column). When I select the 3 columns and chose to make a line graph I get a graph with 3 groups .... time being one of the groups. And as x axis labels (where it should be my time values) it says 'untitled 1' 'untitled 2' etc for each time step. I'm not sure how to make numbers realize that my first column is supposed to be my x axis?
    Also (less importantly) I need to identify what different areas under the graphs are. Since I've got 2 groups and they criss cross, different sections represent different things, and I'd like to put different colours under different areas of the graph, then just make a legend of what the different colours represent. Is this possible? If not I was just going to put labels in and make a legend of the labels...
    Cheers

    You aren't constrained to using a Header Column for the X-Range, if you Format the column you want to use as the X-range as Text.
    Thanks Jerry
    I forgot that and, as I got no response when I asked about it some days ago I thought that there was no workaround.
    Now I know the solution and will try to remember it
    Yvan KOENIG (from FRANCE lundi 3 novembre 2008 14:42:04)

  • Plotting x and y axis from two different data

    Hi everyone,
    I've just started using LabView on my new job. My new task is to create a VI to display a plot an XY graph from two data. How do I actually assign the two different data (X and Y axis resepctively)and plot them out on a same graph??
    Please help me out... my job is on the line!

    Other may post an example for you.
    I will tell how to find this and many other answers.
    Do a "Find Examples" from either the LV open screen or from the Help drop down.
    LV ships with examples that demonstrate almost every basic operation.
    One of the big benifits of these examples is that they work! If they do not, NI is interested in finding which ones do not.
    Ben
    Ben Rayner
    I am currently active on.. MainStream Preppers
    Rayner's Ridge is under construction

  • 3d Surface plot in 2013 - Z axis range input or property node doesn't get updated on the graph

    I point the problem to the  ( 3D_Plot.lvclass.graph Update.vi).
    Can someone confirm this?

    This works for me.  If this is not what you're doing, or if this does not work for you, please provide more details.
    Attachments:
    3Dplot.vi ‏19 KB

  • How to plot semi log graph?

    I am dealing with circuit in which resistance is automatically varying(IC AD633).I want to plot graph of Voltage against this variable resistance.Also as the  range of variation is very large I want to use semi log graph.Is it possible in Multisim? Please reply as soon as possible.

    Hello,
    In the Grapher View you can configure scale, range, etc. Double-click the Grapher View area to open its Properties. There, you can configure the Left/Right axis and the Top/Bottom axis. For example, you can select a Linear scale for the bottom axis and a Logarithmic scale for the left axis to create a semi-log graph.
    Regards,
    Fernando D.
    National Instruments

  • URGENT. Need to make plots with semilog-axis....HOW?

    URGENT. Is there any free classes/packages that are useful in plotting data?
    My plots should have semilog-axis, so that y-axis is logarithmig (intensity) and x-axis linear (time). There is no need for regressing or something like that, only points in the chart. Semilog-axis -feature is essential.
    I found a website: www.vni.com/products/imsl/jmsl_transition.html
    and it sounds promising, but I found no way to download the package!!!!
    I should also generate gif/jpeg/... image from that plot, but I think I can handle that...
    Thanks,
    krera.

    But it doesn't include semilog-axis.... (I think)JFreeChart does have a logarithmic axis feature. In version 0.8.1 only the y-axis can use a logarithmic scale.
    In the CVS version of JFreeChart (on SourceForge) there is now a corresponding feature for the x-axis too. This was contributed by one of the many developers that have submitted code to the project.
    Take a look at the displayTimeSeries2Chart() method in the JFreeChartDemo.java source file for an example
    of how to replace a standard axis with a logarithmic axis.
    Regards,
    Dave Gilbert
    JFreeChart Project Leader

Maybe you are looking for