= to ==, why? [SOLVED]

[Han]

In your third example, just comment out the export equ line (so that equ is created as a CAS variable) for a quick fix.

(12-10-2016 07:07 PM)compsystems Wrote:  The second version "deductionQuadFormula_2()" (works fine), to show intermediate steps, is required to convert it to string. An alternative code may exist

Why are you converting the CAS operations into strings? You can simply print the strings that show what steps you are doing, and then evaluate the actual operations using the actual CAS commands rather than using expr(...).

Code:

print("> factor(answer)");
equ:=factor(equ);
print("> " + equ);

Quote:The third version "deductionQuadFormula_3()", same as the previous one but using a subfunction to not repeat code (it does not work). An alternative code may exist, Who can code it?

Unless the images provide information that your code itself cannot generate, there is really no need to include them because it makes your post that much more difficult to read. Also, please don't edit your original post in that manner. Instead, insert "EDIT:" and add more to your post. Otherwise, when existing responses to your original text it may no longer make sense since you have changed your original post.

Anyway, here is an incomplete example (run as quad(0) or quad(1) for no pause or with pause).

PHP Code:

#cas
quad(p):=
BEGIN
  local eq;

  print("Quadratic Formula");

  dostep('assume(a>0)',p);
  dostep('equ1:=a*x^2+b*x+c=0',p); 
  dostep('equ1:=equ1*4*a',p);
  dostep('equ1:=expand(equ1)',p);
  dostep('equ1:=equ1+b^2-4*a*c',p);
  dostep('equ1:=simplify(equ1)',p);
  dostep('equ1:=factor(equ1)',p);
  // more steps here
END;

dostep(cas,p):=
begin
  print(cas);
  print(eval(cas)); // or use print("> " + eval(cas))
  if p then
    print("                                                                [PAUSE]");
    wait();
  else
    print("");
  end; 
end;
#end 


Here's an alternative that prints something different from what is actually being computed.

PHP Code:

#cas
quad(p):=
BEGIN
  local eq;

  print("Quadratic Formula");

  dostep("assume(a>0)",'assume(a>0)',p);
  dostep("equ1:=a*ax^2+b*x+c=0",'equ1:=a*x^2+b*x+c=0',p); 
  dostep("answer * 4*a",'equ1:=equ1*4*a',p);
  dostep("expand(answer)",'equ1:=expand(equ1)',p);
  dostep("answer + b^2-4*a*c",'equ1:=equ1+b^2-4*a*c',p);
  dostep("simpify(answer)",'equ1:=simplify(equ1)',p);
  dostep("factor(answer)",'equ1:=factor(equ1)',p);
  // more steps here
END;

dostep(s,cas,p):=
begin
  print("> "+s);
  print(eval(cas));
  if p then
    print("                                                                [PAUSE]");
    wait();
  else
    print("");
  end; 
end;
#end