else does nto return expected value
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Hello everyone, I have recently joined so I am a newbie. I only have taken one C++ course but am mostly self-taught by you wonderful people in the forums. I used forums to teach myself VBE so now I am using them to get better at C++. Just to be clear, my programming can be akin to a caveman putting a square peg in a round hole, i.e. it won't be pretty but eventually it will get there. Question I have is, with the following code I kind of expected a zero value to be passed to x when the else part and the if-else was triggered, but it returns an abnormally huge value. This is a .dll being called from VBE. Please forgive me if I have posted wrong, it is my first post. <pre></pre> #include <iostream> using namespace std; #include <cmath> double __stdcall Ts_P(double &arg)//psia input, DegF output { double h_reg_1; double h_reg_2; double h_reg_3; double h_reg_4; double x; double vl_reg1[10] = {1167.0521452767, -724213.16703206, -17.073846940092, 12020.82470247,-3232555.0322333, 14.91510861353, -4823.2657361591, 405113.40542057, -0.23855557567849, 650.17534844798}; double p = (arg * 0.0068947572); //convert psia to MPa double beta = pow(p,0.25); if(p >= 0.000611657 && p <= 22.06495) { h_reg_1 = pow(beta,2) + vl_reg1[2] * beta + vl_reg1[5];//IFC 97 E term h_reg_2 = vl_reg1[0] * pow(beta,2) + vl_reg1[3] * beta + vl_reg1[6];//IFC 97 F term h_reg_3 = vl_reg1[1] * pow(beta,2) + vl_reg1[4] * beta + vl_reg1[7];//IFC 97 G term h_reg_4 = (2 * h_reg_3) / ((-1*h_reg_2) - (pow((pow(h_reg_2,2) - 4 * h_reg_1 * h_reg_3), 0.5)));//IFC 97 D term x = (((vl_reg1[9] + h_reg_4 - pow((pow((vl_reg1[9] + h_reg_4),2) - 4 * (vl_reg1[8] + vl_reg1[9] * h_reg_4)),0.5)) / 2) - 273.15) * (1.8) + 32; return(x); } else{ x=0; return(x); } } </pre>
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Hello everyone, I have recently joined so I am a newbie. I only have taken one C++ course but am mostly self-taught by you wonderful people in the forums. I used forums to teach myself VBE so now I am using them to get better at C++. Just to be clear, my programming can be akin to a caveman putting a square peg in a round hole, i.e. it won't be pretty but eventually it will get there. Question I have is, with the following code I kind of expected a zero value to be passed to x when the else part and the if-else was triggered, but it returns an abnormally huge value. This is a .dll being called from VBE. Please forgive me if I have posted wrong, it is my first post. <pre></pre> #include <iostream> using namespace std; #include <cmath> double __stdcall Ts_P(double &arg)//psia input, DegF output { double h_reg_1; double h_reg_2; double h_reg_3; double h_reg_4; double x; double vl_reg1[10] = {1167.0521452767, -724213.16703206, -17.073846940092, 12020.82470247,-3232555.0322333, 14.91510861353, -4823.2657361591, 405113.40542057, -0.23855557567849, 650.17534844798}; double p = (arg * 0.0068947572); //convert psia to MPa double beta = pow(p,0.25); if(p >= 0.000611657 && p <= 22.06495) { h_reg_1 = pow(beta,2) + vl_reg1[2] * beta + vl_reg1[5];//IFC 97 E term h_reg_2 = vl_reg1[0] * pow(beta,2) + vl_reg1[3] * beta + vl_reg1[6];//IFC 97 F term h_reg_3 = vl_reg1[1] * pow(beta,2) + vl_reg1[4] * beta + vl_reg1[7];//IFC 97 G term h_reg_4 = (2 * h_reg_3) / ((-1*h_reg_2) - (pow((pow(h_reg_2,2) - 4 * h_reg_1 * h_reg_3), 0.5)));//IFC 97 D term x = (((vl_reg1[9] + h_reg_4 - pow((pow((vl_reg1[9] + h_reg_4),2) - 4 * (vl_reg1[8] + vl_reg1[9] * h_reg_4)),0.5)) / 2) - 273.15) * (1.8) + 32; return(x); } else{ x=0; return(x); } } </pre>
First, if it's returning a large value, then my suggestion as that 'p' is between 0.000611657 && 22.06495. On the other hand, how do you know that x was assigned '0'? Second, for programming clarity, may I suggest one of the following: (my preference is #2) 1. getting rid of the two returns and have only one return after the closing brace ({) of the else,
if (a)
{
...
b = 1
}
else
{
b = 2
}
return b;2. OR, remove the else
if (a)
{
b = 1;
return b;
}b = 2;
return b;"If your actions inspire others to dream more, learn more, do more and become more, you are a leader." - John Quincy Adams
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Hello everyone, I have recently joined so I am a newbie. I only have taken one C++ course but am mostly self-taught by you wonderful people in the forums. I used forums to teach myself VBE so now I am using them to get better at C++. Just to be clear, my programming can be akin to a caveman putting a square peg in a round hole, i.e. it won't be pretty but eventually it will get there. Question I have is, with the following code I kind of expected a zero value to be passed to x when the else part and the if-else was triggered, but it returns an abnormally huge value. This is a .dll being called from VBE. Please forgive me if I have posted wrong, it is my first post. <pre></pre> #include <iostream> using namespace std; #include <cmath> double __stdcall Ts_P(double &arg)//psia input, DegF output { double h_reg_1; double h_reg_2; double h_reg_3; double h_reg_4; double x; double vl_reg1[10] = {1167.0521452767, -724213.16703206, -17.073846940092, 12020.82470247,-3232555.0322333, 14.91510861353, -4823.2657361591, 405113.40542057, -0.23855557567849, 650.17534844798}; double p = (arg * 0.0068947572); //convert psia to MPa double beta = pow(p,0.25); if(p >= 0.000611657 && p <= 22.06495) { h_reg_1 = pow(beta,2) + vl_reg1[2] * beta + vl_reg1[5];//IFC 97 E term h_reg_2 = vl_reg1[0] * pow(beta,2) + vl_reg1[3] * beta + vl_reg1[6];//IFC 97 F term h_reg_3 = vl_reg1[1] * pow(beta,2) + vl_reg1[4] * beta + vl_reg1[7];//IFC 97 G term h_reg_4 = (2 * h_reg_3) / ((-1*h_reg_2) - (pow((pow(h_reg_2,2) - 4 * h_reg_1 * h_reg_3), 0.5)));//IFC 97 D term x = (((vl_reg1[9] + h_reg_4 - pow((pow((vl_reg1[9] + h_reg_4),2) - 4 * (vl_reg1[8] + vl_reg1[9] * h_reg_4)),0.5)) / 2) - 273.15) * (1.8) + 32; return(x); } else{ x=0; return(x); } } </pre>
(please reformat your code). Have you use the debugger to check the values and the code flow ?
Watched code never compiles.
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First, if it's returning a large value, then my suggestion as that 'p' is between 0.000611657 && 22.06495. On the other hand, how do you know that x was assigned '0'? Second, for programming clarity, may I suggest one of the following: (my preference is #2) 1. getting rid of the two returns and have only one return after the closing brace ({) of the else,
if (a)
{
...
b = 1
}
else
{
b = 2
}
return b;2. OR, remove the else
if (a)
{
b = 1;
return b;
}b = 2;
return b;"If your actions inspire others to dream more, learn more, do more and become more, you are a leader." - John Quincy Adams
Thank you for your reply. Actually what the code computes is the steam saturation temperature given pressure. The abnormally large value comes in when the p is not between the 0.000611657 and 22.06495. I had no luck with your modification, I am assumin it is in the syntax but have had no luck thus far.
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(please reformat your code). Have you use the debugger to check the values and the code flow ?
Watched code never compiles.
When you say please reformat the code I am not sure what you are suggesting. When I try to run the debugger it says that it cannot open the .dll file that was created. The only way I can run it is to open up the excel file that references the .dll and plug in values for p that are either inside or outside of the range of the if statement and view the results.
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Thank you for your reply. Actually what the code computes is the steam saturation temperature given pressure. The abnormally large value comes in when the p is not between the 0.000611657 and 22.06495. I had no luck with your modification, I am assumin it is in the syntax but have had no luck thus far.
you posted
if(p >= 0.000611657 && p <= 22.06495)
which fixed up reads:
if(p >= 0.000611657 && p <= 22.06495)
so that means p would be between 0.000611657 && 22.06495 if you want p to be outside that range, then change it to read
if(p < 0.000611657 || p > 22.06495)
"If your actions inspire others to dream more, learn more, do more and become more, you are a leader." - John Quincy Adams
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Thank you for your reply. Actually what the code computes is the steam saturation temperature given pressure. The abnormally large value comes in when the p is not between the 0.000611657 and 22.06495. I had no luck with your modification, I am assumin it is in the syntax but have had no luck thus far.
also, have you tried attaching the code to a debugger and stepping through to see what actually happens? if you can't do that, then try using some tracing statements to see what the values are and where the logic actually flows.
"If your actions inspire others to dream more, learn more, do more and become more, you are a leader." - John Quincy Adams
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you posted
if(p >= 0.000611657 && p <= 22.06495)
which fixed up reads:
if(p >= 0.000611657 && p <= 22.06495)
so that means p would be between 0.000611657 && 22.06495 if you want p to be outside that range, then change it to read
if(p < 0.000611657 || p > 22.06495)
"If your actions inspire others to dream more, learn more, do more and become more, you are a leader." - John Quincy Adams
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I may not be clear on the code. p must be between these ranges for the calculation to execute, if it is outside of these ranges then the calculation does not apply and I want a 0 or a -1 returned.
ah ok, then my question still is, how do you know that x is being assigned 0? or that p is NOT in the desired range?
"If your actions inspire others to dream more, learn more, do more and become more, you are a leader." - John Quincy Adams
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When you say please reformat the code I am not sure what you are suggesting. When I try to run the debugger it says that it cannot open the .dll file that was created. The only way I can run it is to open up the excel file that references the .dll and plug in values for p that are either inside or outside of the range of the if statement and view the results.
attach the debugger to excel. and make sure the dll is loaded before the offending code is called (or call it at least once). then set a breakpoint in the offending code file. and cause excel to call the function.
"If your actions inspire others to dream more, learn more, do more and become more, you are a leader." - John Quincy Adams
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ah ok, then my question still is, how do you know that x is being assigned 0? or that p is NOT in the desired range?
"If your actions inspire others to dream more, learn more, do more and become more, you are a leader." - John Quincy Adams
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Only in that from the Excel spreadsheet where I am entering the variable p into the function I can set it so that it is outside of the range of the if statement parameters. The value is returns when this is so is something like 1.7878e+308.
Try throwing in some MessageBox's so you can so the values in the method and the logic flow...
"If your actions inspire others to dream more, learn more, do more and become more, you are a leader." - John Quincy Adams
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Try throwing in some MessageBox's so you can so the values in the method and the logic flow...
"If your actions inspire others to dream more, learn more, do more and become more, you are a leader." - John Quincy Adams
I played with the code, this returns the values I need: double __stdcall Ts_P(double &arg)//psia input, DegF output { double h_reg_1; double h_reg_2; double h_reg_3; double h_reg_4; double x; double vl_reg1[10] = {1167.0521452767, -724213.16703206, -17.073846940092, 12020.82470247,-3232555.0322333, 14.91510861353, -4823.2657361591, 405113.40542057, -0.23855557567849, 650.17534844798}; double p = (arg * 0.0068947572); //convert psia to MPa double beta = pow(p,0.25); if(p >= 0.000611657 && p <= 22.06495) { h_reg_1 = pow(beta,2) + vl_reg1[2] * beta + vl_reg1[5];//IFC 97 E term h_reg_2 = vl_reg1[0] * pow(beta,2) + vl_reg1[3] * beta + vl_reg1[6];//IFC 97 F term h_reg_3 = vl_reg1[1] * pow(beta,2) + vl_reg1[4] * beta + vl_reg1[7];//IFC 97 G term h_reg_4 = (2 * h_reg_3) / ((-1*h_reg_2) - (pow((pow(h_reg_2,2) - 4 * h_reg_1 * h_reg_3), 0.5)));//IFC 97 D term x = (((vl_reg1[9] + h_reg_4 - pow((pow((vl_reg1[9] + h_reg_4),2) - 4 * (vl_reg1[8] + vl_reg1[9] * h_reg_4)),0.5)) / 2) - 273.15) * (1.8) + 32; return(x); } else { x=-1; } return(x); }
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I played with the code, this returns the values I need: double __stdcall Ts_P(double &arg)//psia input, DegF output { double h_reg_1; double h_reg_2; double h_reg_3; double h_reg_4; double x; double vl_reg1[10] = {1167.0521452767, -724213.16703206, -17.073846940092, 12020.82470247,-3232555.0322333, 14.91510861353, -4823.2657361591, 405113.40542057, -0.23855557567849, 650.17534844798}; double p = (arg * 0.0068947572); //convert psia to MPa double beta = pow(p,0.25); if(p >= 0.000611657 && p <= 22.06495) { h_reg_1 = pow(beta,2) + vl_reg1[2] * beta + vl_reg1[5];//IFC 97 E term h_reg_2 = vl_reg1[0] * pow(beta,2) + vl_reg1[3] * beta + vl_reg1[6];//IFC 97 F term h_reg_3 = vl_reg1[1] * pow(beta,2) + vl_reg1[4] * beta + vl_reg1[7];//IFC 97 G term h_reg_4 = (2 * h_reg_3) / ((-1*h_reg_2) - (pow((pow(h_reg_2,2) - 4 * h_reg_1 * h_reg_3), 0.5)));//IFC 97 D term x = (((vl_reg1[9] + h_reg_4 - pow((pow((vl_reg1[9] + h_reg_4),2) - 4 * (vl_reg1[8] + vl_reg1[9] * h_reg_4)),0.5)) / 2) - 273.15) * (1.8) + 32; return(x); } else { x=-1; } return(x); }
congratulations! good for you!
"If your actions inspire others to dream more, learn more, do more and become more, you are a leader." - John Quincy Adams
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congratulations! good for you!
"If your actions inspire others to dream more, learn more, do more and become more, you are a leader." - John Quincy Adams
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When you say please reformat the code I am not sure what you are suggesting. When I try to run the debugger it says that it cannot open the .dll file that was created. The only way I can run it is to open up the excel file that references the .dll and plug in values for p that are either inside or outside of the range of the if statement and view the results.
jharn wrote:
When you say please reformat the code I am not sure what you are suggesting.
Your code snippet is barely readable, since all special characters are escaped and the formatting is not kept. Check the forum guidelines (the message "How to ask a question" on top of this message board). The point nr 7 explains exactly what you have to do when you want to paste a code snippet.
Cédric Moonen Software developer
Charting control [v3.0] OpenGL game tutorial in C++ -
Hello everyone, I have recently joined so I am a newbie. I only have taken one C++ course but am mostly self-taught by you wonderful people in the forums. I used forums to teach myself VBE so now I am using them to get better at C++. Just to be clear, my programming can be akin to a caveman putting a square peg in a round hole, i.e. it won't be pretty but eventually it will get there. Question I have is, with the following code I kind of expected a zero value to be passed to x when the else part and the if-else was triggered, but it returns an abnormally huge value. This is a .dll being called from VBE. Please forgive me if I have posted wrong, it is my first post. <pre></pre> #include <iostream> using namespace std; #include <cmath> double __stdcall Ts_P(double &arg)//psia input, DegF output { double h_reg_1; double h_reg_2; double h_reg_3; double h_reg_4; double x; double vl_reg1[10] = {1167.0521452767, -724213.16703206, -17.073846940092, 12020.82470247,-3232555.0322333, 14.91510861353, -4823.2657361591, 405113.40542057, -0.23855557567849, 650.17534844798}; double p = (arg * 0.0068947572); //convert psia to MPa double beta = pow(p,0.25); if(p >= 0.000611657 && p <= 22.06495) { h_reg_1 = pow(beta,2) + vl_reg1[2] * beta + vl_reg1[5];//IFC 97 E term h_reg_2 = vl_reg1[0] * pow(beta,2) + vl_reg1[3] * beta + vl_reg1[6];//IFC 97 F term h_reg_3 = vl_reg1[1] * pow(beta,2) + vl_reg1[4] * beta + vl_reg1[7];//IFC 97 G term h_reg_4 = (2 * h_reg_3) / ((-1*h_reg_2) - (pow((pow(h_reg_2,2) - 4 * h_reg_1 * h_reg_3), 0.5)));//IFC 97 D term x = (((vl_reg1[9] + h_reg_4 - pow((pow((vl_reg1[9] + h_reg_4),2) - 4 * (vl_reg1[8] + vl_reg1[9] * h_reg_4)),0.5)) / 2) - 273.15) * (1.8) + 32; return(x); } else{ x=0; return(x); } } </pre>
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When you say please reformat the code I am not sure what you are suggesting. When I try to run the debugger it says that it cannot open the .dll file that was created. The only way I can run it is to open up the excel file that references the .dll and plug in values for p that are either inside or outside of the range of the if statement and view the results.
I think what he means is that you should use the formatting that this forum provides, either by marking your code block and clicking on the beige-underlined formatting button titled
code block, or by manually surrounding your code block with the tags<pre>and</pre>. It should then look something like this in your editor window:if (a) {
b = 1;
}
else {
b = 0;
}(that last <pre> should have been </pre> instead actually, but that would have prematurely ended my example since I used the same tags to format it in the first place :) )