No announcement yet.

Editing symbols for export into shape file

  • Filter
  • Time
  • Show
Clear All
new posts

  • Editing symbols for export into shape file

    I have received a canvas file from another user that created it with a past canvas version about 5-10 years ago. There are a mixture of symbols on the file, and I am not quite sure how they were created and how they differ from one another. When I go to export the symbols into a shapefile so that I can geoprocess them, one set turns into two or three line objects, which I can work with, and the other symbols turn into a problematic line outline of the symbol. I am trying to find a method of just exporting a simple set of lines (or line) that best represent the object rather than an outline of those objects. Is there anyway to easily replace the current objects in a layer with a simple symbol that will turn into simple lines in a shape file? I just need to preserve the line orientations and location of the accompanying central bulge, but nothing else.

    These are the objects I have having trouble with. They export as an outline. These are some of the objects that export correctly. These one are composed of one object, but when exported into a shapefile, become three lines, one for the line, and two for the box. This works.

  • #2
    Hi CofMaine37,

    I am replying so you don't think the community is ignoring you. But I have only failure to report.

    Over the years I have made a small personal, eclectic, collection of geological symbols that I have created as polygons or grouped polygons etc similar to ones shown in your image. (We should put in a request for a set of geo-symbols there are a few geos that use Canvas to produce maps). I pulled a symbol into a Canvas document and then saved the document, using the selected option to select only the symbol, as a .shp file (plus the other three files that come with a.shp file). When I opened the .shp file in MapInfo v2015, with no other .tab files open, all I could see was a straight line. The meaningful bits to indicate that this was a joint, a fault symbol etc had disappeared. I suspect it has to do with the coordinate system that is embedded in the .shp file as I have found MapInfo very unforgiving in that regard.

    My next experiment was to open the file in Golden Software's Surfer v15. An error message popped up saying that there was a problem with embedded projection. Once I got past the error message a polyline outline of the image, in this case a bedding dip symbol did appear on the Surfer Plot page. It occupied the full page, it was a polyline object and the coordinate system was the page's centimetre scale. I had the same experience trying to import the .shp file into Golden Software's Didger v5. But there I selected "cartesian coordinates" and did not get an error message the symbol just opened full page. So not much joy from me I am afraid.

    I shall watch this space with interest to see whether others have a solution for you.


    • #3
      I wrote a program years ago (last updated in 2014) which would take a table of geological orientations and produce a text file that could be read into Canvas as a GIS text file for plotting orientations like this. I don't know if your Canvas file was produced with the help of my software or not. my software is still posted at:


      • #4
        By the way, the geological symbols in your first picture are foliations or cleavages; the second symbol with the black boxes in the middle are joints. My software would tag these symbols as _SHAPE_TAG_=AREA.


        • #5
          Any way to get a copy of that Canvas file?


          • #6
            Originally posted by ajimenez View Post
            Any way to get a copy of that Canvas file?
            Hi Albert,

            A lot of geologists still use Canvas to make maps and symbols such as these -- whose orientation on the page depends on the underlying measurement that a geologist made with a compass (or now smartphone) at a specific place -- are an extremely common feature of most geologist maps. My software is a kludge that works but is cumbersome. having the ability to do all of this in Canvas GIS and avoid my primitive third party solution would be great.


            • #7
              I understand and would love for you to continue to use our product. Just thought that if anyone had a Canvas file with such symbols, it would be a bit faster to get to the bottom of this. Thank you...