Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Special Interest Groups
  3. Independent Developers
  4. math function failing

math function failing

Scheduled Pinned Locked Moved Unsolved Independent Developers
18 Posts 4 Posters 2.5k Views
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • S SGaist
    15 Aug 2022, 18:37

    From the looks of it, you are not linking to the math library.

    G Offline
    G Offline
    goswami
    wrote on 16 Aug 2022, 06:10 last edited by
    #9

    @SGaist Yes but why so is not clear. Single file with math.h is working OK. Where the linker related setting and how it can be fixed is my question.

    1 Reply Last reply
    0
    • M mrjj
      14 Aug 2022, 15:32

      Hi
      -Can anybody throw some light why the same is happening despite math.h is included in the same file?

      Well if you are not on the same platform, it can be that Cmake cant find the math lib to link against.

      • . Is there anyway to know what to do if no response is given in the forum?

      There are other coding places to ask also. Like StackOverflow.
      But make sure you write good questions as it's impossible to help if clear information is not
      provided.

      But normally we do answer most questions here :)

      G Offline
      G Offline
      goswami
      wrote on 16 Aug 2022, 06:24 last edited by
      #10

      @mrjj it is linking time problem undestood but do not know how to fix it in Qt. Single file with #include<math.h> is working alright. Pl. advise if any other sources to explore for the solution.

      J 1 Reply Last reply 16 Aug 2022, 07:41
      0
      • G goswami
        16 Aug 2022, 06:24

        @mrjj it is linking time problem undestood but do not know how to fix it in Qt. Single file with #include<math.h> is working alright. Pl. advise if any other sources to explore for the solution.

        J Offline
        J Offline
        JonB
        wrote on 16 Aug 2022, 07:41 last edited by
        #11

        @goswami
        Please show the linker line being executed. So far as I am aware, linking with math library is achieved via -lm option.

        G 1 Reply Last reply 16 Aug 2022, 13:08
        2
        • J JonB
          16 Aug 2022, 07:41

          @goswami
          Please show the linker line being executed. So far as I am aware, linking with math library is achieved via -lm option.

          G Offline
          G Offline
          goswami
          wrote on 16 Aug 2022, 13:08 last edited by
          #12

          @JonB I am using Qt IDE with cmake for building. Following code is working alright
          #include <stdio.h>
          #include <math.h>
          int main()
          {
          printf("Hello World!=%f\n",pow(2.0,2.0));
          return 0;
          }

          And CMakeLists.txt content is as below
          cmake_minimum_required(VERSION 3.5)
          project(untitled1 LANGUAGES C)
          add_executable(untitled1 main.c)

          I do not know how to check linker option in Qt IDE. This is reasonably big project and impossible to go for command line building.

          J 1 Reply Last reply 16 Aug 2022, 13:11
          0
          • G goswami
            16 Aug 2022, 13:08

            @JonB I am using Qt IDE with cmake for building. Following code is working alright
            #include <stdio.h>
            #include <math.h>
            int main()
            {
            printf("Hello World!=%f\n",pow(2.0,2.0));
            return 0;
            }

            And CMakeLists.txt content is as below
            cmake_minimum_required(VERSION 3.5)
            project(untitled1 LANGUAGES C)
            add_executable(untitled1 main.c)

            I do not know how to check linker option in Qt IDE. This is reasonably big project and impossible to go for command line building.

            J Offline
            J Offline
            JonB
            wrote on 16 Aug 2022, 13:11 last edited by
            #13

            @goswami said in math function failing:

            I do not know how to check linker option in Qt IDE

            Did you try looking in the Build Output pane? I don't know, that would be my guess. And I don't know about cmake so I'll leave you with others to respond.

            G 1 Reply Last reply 16 Aug 2022, 13:20
            0
            • J JonB
              16 Aug 2022, 13:11

              @goswami said in math function failing:

              I do not know how to check linker option in Qt IDE

              Did you try looking in the Build Output pane? I don't know, that would be my guess. And I don't know about cmake so I'll leave you with others to respond.

              G Offline
              G Offline
              goswami
              wrote on 16 Aug 2022, 13:20 last edited by
              #14

              @JonB Thanks for trying to help.

              1 Reply Last reply
              0
              • S Offline
                S Offline
                SGaist
                Lifetime Qt Champion
                wrote on 16 Aug 2022, 17:34 last edited by
                #15
                target_link_libraries(untitled1 m)
                

                Interested in AI ? www.idiap.ch
                Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                G 1 Reply Last reply 18 Aug 2022, 12:58
                2
                • S SGaist
                  16 Aug 2022, 17:34
                  target_link_libraries(untitled1 m)
                  
                  G Offline
                  G Offline
                  goswami
                  wrote on 18 Aug 2022, 12:58 last edited by
                  #16

                  @SGaist said in math function failing:

                  target_link_libraries(untitled1 m)

                  Many thanks all math.h related errors have gone and the application is giving output. Can you throw some light why the same is not failing when only one file with math.h include is there? Another as it is appearing all #include of libraries are not creating problem. Is it system dependant viz. may compile in one environment but fail in somewhere?
                  I am really grateful over the efforts you have put to help me out of this crisis which became a serious bottleneck for progress to next stage.

                  1 Reply Last reply
                  0
                  • S Offline
                    S Offline
                    SGaist
                    Lifetime Qt Champion
                    wrote on 18 Aug 2022, 18:29 last edited by
                    #17

                    It depends on the library and what is used of them.

                    Some are header only, some are template based so it really depends on what you use from these and how they are implemented. It's usually not tied to a specific OS.

                    Interested in AI ? www.idiap.ch
                    Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                    G 1 Reply Last reply 21 Aug 2022, 10:24
                    0
                    • S SGaist
                      18 Aug 2022, 18:29

                      It depends on the library and what is used of them.

                      Some are header only, some are template based so it really depends on what you use from these and how they are implemented. It's usually not tied to a specific OS.

                      G Offline
                      G Offline
                      goswami
                      wrote on 21 Aug 2022, 10:24 last edited by
                      #18

                      @SGaist Thank you very much for updating me.

                      1 Reply Last reply
                      0

                      18/18

                      21 Aug 2022, 10:24

                      • Login

                      • Login or register to search.
                      18 out of 18
                      • First post
                        18/18
                        Last post
                      0
                      • Categories
                      • Recent
                      • Tags
                      • Popular
                      • Users
                      • Groups
                      • Search
                      • Get Qt Extensions
                      • Unsolved