why can't my perceptron learn correctly?

This is a discussion on why can't my perceptron learn correctly? within the C Programming forums, part of the General Programming Boards category; hi, my perceptron seems not to be able of calculating the correct output if the output is bigger than the ...

  1. #1
    Registered User yann's Avatar
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    why can't my perceptron learn correctly?

    hi, my perceptron seems not to be able of calculating the correct output if the output is bigger than the weights , here's my code...

    Code:
    #include <stdio.h>
    #define LR 0.1
    int wantedout;
    int out;
    int input1=0;
    int input2=1;
    long weight1=50;
    long weight2=50;
    int error;
    educate_net()
    {
    out  = ((input1*weight1) + (input2*weight2));
    error = out - wantedout;
    weight1 = weight1 - (error*LR);   
    weight2 = weight2 - (error*LR);
    }
    int main(){
    printf("wanted output:");
    while(1==1){
    scanf("%d", &wantedout);
    while(wantedout != out){
    educate_net();
    printf("%d\n", out);
    }
    }
    return 0;
    }

    so, if the wantedout is bigger than the weight1 and weight 2...it just goes to infinite loop, do you know why and how can i fix it? please...

  2. #2
    ATH0 quzah's Avatar
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    1. Your indentation is terrible. (You don't have any!)
    2. You use out without initializing it.
    3. You check to see if wantedout is what you want, before you ever do anything with it.


    Quzah.
    Hope is the first step on the road to disappointment.

  3. #3
    MTK
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  4. #4
    Registered User yann's Avatar
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    srry, but i initialise out... and i do chek wantedout... sorry about the indentitation
    Arduino rocks!

  5. #5
    ATH0 quzah's Avatar
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    No you don't, and no you didn't. Here's your code, indented:
    Code:
    #include <stdio.h>
    #define LR 0.1
    int wantedout;
    int out;    <--- not initialized
    int input1=0;
    int input2=1;
    long weight1=50;
    long weight2=50;
    int error;
    educate_net()
    {
        out  = ((input1*weight1) + (input2*weight2));
        error = out - wantedout;
        weight1 = weight1 - (error*LR);   
        weight2 = weight2 - (error*LR);
    }
    int main(){
        printf("wanted output:");
        while(1==1){
            scanf("%d", &wantedout);
            while(wantedout != out){  <--- checking the value before...
                educate_net();        <--- ...you actually modify them
                printf("%d\n", out);
            }
        }
        return 0;
    }

    Quzah.
    Hope is the first step on the road to disappointment.

  6. #6
    Registered User yann's Avatar
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    Quote Originally Posted by quzah View Post
    No you don't, and no you didn't. Here's your code, indented:
    Code:
    #include <stdio.h>
    #define LR 0.1
    int wantedout;
    int out;    <--- not initialized
    int input1=0;
    int input2=1;
    long weight1=50;
    long weight2=50;
    int error;
    educate_net()
    {
        out  = ((input1*weight1) + (input2*weight2));
        error = out - wantedout;
        weight1 = weight1 - (error*LR);   
        weight2 = weight2 - (error*LR);
    }
    int main(){
        printf("wanted output:");
        while(1==1){
            scanf("%d", &wantedout);
            while(wantedout != out){  <--- checking the value before...
                educate_net();        <--- ...you actually modify them
                printf("%d\n", out);
            }
        }
        return 0;
    }

    Quzah.
    ok, but, do i need to in. out when it will be calculated?
    Arduino rocks!

  7. #7
    MTK
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    Pay a little more attention to the red highlighted parts.

  8. #8
    spurious conceit MK27's Avatar
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    Quote Originally Posted by yann View Post
    ok, but, do i need to in. out when it will be calculated?
    Technically, gcc and I think probably most compilers will initialize a global to 0 for you, but that is not guaranteed by the standard, so you should not assume that a variable you didn't initialize has any particular value.

    In other words, out could be any number initially. What if wantedout == out? The user sets wantedout, but there is no way to say for sure what out is the first time.
    C programming resources:
    GNU C Function and Macro Index -- glibc reference manual
    The C Book -- nice online learner guide
    Current ISO draft standard
    CCAN -- new CPAN like open source library repository
    3 (different) GNU debugger tutorials: #1 -- #2 -- #3
    cpwiki -- our wiki on sourceforge

  9. #9
    ATH0 quzah's Avatar
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    Your outer loop retains the old values however, so after giving you the right results for the first loop, it breaks after that. I don't know if that's intentional. I'd guess probably not, but then I don't know what you're really trying to do with your program, so who knows?

    Quzah.
    Hope is the first step on the road to disappointment.

  10. #10
    Frequently Quite Prolix dwks's Avatar
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    Quote Originally Posted by MK27 View Post
    Technically, gcc and I think probably most compilers will initialize a global to 0 for you, but that is not guaranteed by the standard, so you should not assume that a variable you didn't initialize has any particular value.
    Actually, I think that is guaranteed by the standard. Regardless, it's not something you should rely on (especially as a beginning programmer).
    dwk

    Seek and ye shall find. quaere et invenies.

    "Simplicity does not precede complexity, but follows it." -- Alan Perlis
    "Testing can only prove the presence of bugs, not their absence." -- Edsger Dijkstra
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  11. #11
    ATH0 quzah's Avatar
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    Quote Originally Posted by dwks View Post
    Actually, I think that is guaranteed by the standard. Regardless, it's not something you should rely on (especially as a beginning programmer).
    Not if it isn't static it isn't.


    Quzah.
    Hope is the first step on the road to disappointment.

  12. #12
    Ex scientia vera
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    Quote Originally Posted by quzah View Post
    Not if it isn't static it isn't.


    Quzah.
    Yes - global AND static variables are initialized to zero. Or rather, everything that gets put in .bss normally.
    "What's up, Doc?"
    "'Up' is a relative concept. It has no intrinsic value."

  13. #13
    ATH0 quzah's Avatar
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    Quote Originally Posted by IceDane View Post
    Yes - global AND static variables are initialized to zero. Or rather, everything that gets put in .bss normally.
    No. Static yes, global no. (Unless you're saying a static global, but then that's covered under the heading of 'static' already.) Feel free to prove me wrong, but I'm not seeing where it guarantees that global variables are guaranteed default initialization. I could be just too tired to see/find it, but I'm not seeing it.


    Quzah.
    Hope is the first step on the road to disappointment.

  14. #14
    Malum in se abachler's Avatar
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    another little piece of advice is that perceptrons generally need either fixed or floating point weights, inputs and outputs. integers just won't do.
    Until you can build a working general purpose reprogrammable computer out of basic components from radio shack, you are not fit to call yourself a programmer in my presence. This is cwhizard, signing off.

  15. #15
    spurious conceit MK27's Avatar
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    Quote Originally Posted by abachler View Post
    another little piece of advice is that perceptrons generally need either fixed or floating point weights, inputs and outputs. integers just won't do.
    Oh god please no don't do this...
    C programming resources:
    GNU C Function and Macro Index -- glibc reference manual
    The C Book -- nice online learner guide
    Current ISO draft standard
    CCAN -- new CPAN like open source library repository
    3 (different) GNU debugger tutorials: #1 -- #2 -- #3
    cpwiki -- our wiki on sourceforge

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