Simple math in C++ - Revision history

wikademia>Wikademia: moved Simple Math to Simple math in C++

2009-05-17T02:29:21Z

← Older revision	Revision as of 02:29, 17 May 2009
(No difference)

wikademia>Wikademia: 18 revisions

2009-04-11T05:41:05Z

18 revisions

← Older revision	Revision as of 05:41, 11 April 2009
(No difference)

wikademia>Miklcct: rewrite the whole code as it is not ansi-compatible

2009-04-10T12:36:12Z

rewrite the whole code as it is not ansi-compatible

← Older revision		Revision as of 12:36, 10 April 2009
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	----		----

	~~/This program finds prime numbers between 1 and number provided by user/~~
	<code><pre>		<code><pre>
	#include<iostream.h>		#include<iostream>
	~~#include<conio.h>~~		using namespace std;
	~~#include<stdio.h>~~		int main(){
	~~void~~ main()		int n;
	{		cin>>n;
	~~clrscr();~~		for(int i=2;i<n;++i){
	~~unsigned~~ int ~~a,i,~~n~~,x;~~		int count=0;
	~~cout<<"This program is developed by Nirdh... press enter to continue."~~;		for(int j=1;j<=n;++j)
	~~cout<<"Enter a number till which prime numbers are wanted: ";~~		if(!(i%j))
	cin>>a;		++count;
	for(x=1;x<~~a+1~~;x++)		if(count==2)
	{		cout<<i<<endl;
	n=0;		}
	for(i=1;i<=x;i++)		return 0;
	{
	if(x%~~i==0~~)
	{
	~~n=n~~+1;
	}
	~~else~~
	{
	~~n=n;~~
	}
	}
	if(~~n<3~~)
	{
	cout<<x<<~~"\t"~~;
	}
	}
	~~getch()~~;
	}		}
	</pre></code>		</pre></code>

	~~--[[User:Nirdh\|Nirdh]] 11:36, 5 April 2009 (UTC)~~

	----		----



	==Where To Go Next==		==Where To Go Next==

wikademia>Nirdh: added a sample program

2009-04-05T11:36:19Z

added a sample program

@@ Line 80: / Line 80: @@
 === End of lesson 3 ===
-You should now be able to get C++ to do some simple math for you. In reality, it never gets much more complex than this. Almost everything you will write will be based on just a few simple operators. Thanks for reading this far. Hopefully you have learned something.
+You should now be able to get C++ to do some simple math for you. In reality, it never gets much more complex than this. Almost everything you will write will be based on just a few simple operators. Thanks for reading this far. Hopefully you have learned something. Still, for your enhancement, following is the program that finds prime numbers until specified number:
 ==Where To Go Next==

89.134.51.92: /* Basic Math Library Functions */

2008-06-07T18:36:04Z

Basic Math Library Functions

← Older revision		Revision as of 18:36, 7 June 2008
Line 67:		Line 67:
	float myValue=25, myResult;		float myValue=25, myResult;
	myResult = sqrt(myValue); // Squareroot the variable myValue, and store it into variable myResult		myResult = sqrt(myValue); // Squareroot the variable myValue, and store it into variable myResult
	myResult = pow(~~my_result~~,2.00); // Square the variable myResult, and then store it back into myResult		myResult = pow(myResult,2.00); // Square the variable myResult, and then store it back into myResult
	</pre></code>		</pre></code>

206.171.124.194 at 16:50, 16 May 2008

2008-05-16T16:50:43Z

← Older revision		Revision as of 16:50, 16 May 2008
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	</pre></code>		</pre></code>

	C++ will perform operations via ~~BEDMAS~~ (or PEMDAS, or however you learned it in middle school). That means brackets (or parantheses) will be computed first. Then exponents, then division ~~and multiplication~~, and then finally addition and subtraction. The above code will take the number six, and then convert it to a floating point number. Then it will multiply 6 by pi, which will return a floating point number. Then twelve, which has been converted to a float, will be added to the result. So myResult at this point will contain 30.84. Then five will be converted to a float and subtracted from myResult. The result will be 25.84.		C++ will perform operations via BEMDAS (or PEMDAS, or however you learned it in middle school). That means brackets (or parantheses) will be computed first. Then exponents, then multiplication and division, and then finally addition and subtraction. The above code will take the number six, and then convert it to a floating point number. Then it will multiply 6 by pi, which will return a floating point number. Then twelve, which has been converted to a float, will be added to the result. So myResult at this point will contain 30.84. Then five will be converted to a float and subtracted from myResult. The result will be 25.84.

	This should be pretty straightforward. Now, take a look at the last line of the above code. Notice that we are taking the variable and adding another value to it, and then dumping it back into itself. You've just had to type the same variable name twice in a row, which could lead to typos, and also takes up time. There is an easier way to do this! Each of the following lines has an equivalent line of code that follows.		This should be pretty straightforward. Now, take a look at the last line of the above code. Notice that we are taking the variable and adding another value to it, and then dumping it back into itself. You've just had to type the same variable name twice in a row, which could lead to typos, and also takes up time. There is an easier way to do this! Each of the following lines has an equivalent line of code that follows.

206.171.124.194 at 16:49, 16 May 2008

2008-05-16T16:49:01Z

← Older revision		Revision as of 16:49, 16 May 2008
Line 34:		Line 34:
	</pre></code>		</pre></code>

	C++ will perform operations via BEDMAS (or ~~PEDMAS~~, or however you learned it in middle school). That means brackets (or parantheses) will be computed first. Then exponents, then division and multiplication, and then finally addition and subtraction. The above code will take the number six, and then convert it to a floating point number. Then it will multiply 6 by pi, which will return a floating point number. Then twelve, which has been converted to a float, will be added to the result. So myResult at this point will contain 30.84. Then five will be converted to a float and subtracted from myResult. The result will be 25.84.		C++ will perform operations via BEDMAS (or PEMDAS, or however you learned it in middle school). That means brackets (or parantheses) will be computed first. Then exponents, then division and multiplication, and then finally addition and subtraction. The above code will take the number six, and then convert it to a floating point number. Then it will multiply 6 by pi, which will return a floating point number. Then twelve, which has been converted to a float, will be added to the result. So myResult at this point will contain 30.84. Then five will be converted to a float and subtracted from myResult. The result will be 25.84.

	This should be pretty straightforward. Now, take a look at the last line of the above code. Notice that we are taking the variable and adding another value to it, and then dumping it back into itself. You've just had to type the same variable name twice in a row, which could lead to typos, and also takes up time. There is an easier way to do this! Each of the following lines has an equivalent line of code that follows.		This should be pretty straightforward. Now, take a look at the last line of the above code. Notice that we are taking the variable and adding another value to it, and then dumping it back into itself. You've just had to type the same variable name twice in a row, which could lead to typos, and also takes up time. There is an easier way to do this! Each of the following lines has an equivalent line of code that follows.

24.9.49.81: /* Adding, Subtracting, Multiplying and Dividing */

2008-02-09T09:34:16Z

Adding, Subtracting, Multiplying and Dividing

← Older revision		Revision as of 09:34, 9 February 2008
Line 41:		Line 41:
	myResult = myResult+5;		myResult = myResult+5;
	myResult += 5;		myResult += 5;

	myResult = myResult-5;		myResult = myResult-5;
	myResult -= 5;		myResult -= 5;

	myResult = myResult*5;		myResult = myResult*5;
	myResult *= 5;		myResult *= 5;

	myResult = myResult/5;		myResult = myResult/5;
	myResult /= 5;		myResult /= 5;

203.111.234.77: /* Basic Math Library Functions */

2007-08-24T06:56:30Z

Basic Math Library Functions

← Older revision		Revision as of 06:56, 24 August 2007
Line 59:		Line 59:
	=== Basic Math Library Functions ===		=== Basic Math Library Functions ===

	Now it is time to browse a few of the functions that are available from the math library. We can take the square roots of numbers, we can take powers of numbers, etc. The ~~synatax~~ is as follows:		Now it is time to browse a few of the functions that are available from the math library. We can take the square roots of numbers, we can take powers of numbers, etc. The syntax is as follows:

	<code><pre>		<code><pre>
Line 70:		Line 70:

	<code><pre>		<code><pre>
	pow(myValue,~~myPowner~~); // myValue is the base and myPower is the exponent		pow(myValue,myPower); // myValue is the base and myPower is the exponent
	</pre></code>		</pre></code>

	For a list of functions, see [http://en.wikipedia.org/wiki/Math.h math.h].		For a list of functions, see [http://en.wikipedia.org/wiki/Math.h math.h].

	=== End of lesson 3 ===		=== End of lesson 3 ===

wikademia>Reinterpret cast: /* Simple C++ Math */

2007-08-08T02:38:37Z

Simple C++ Math

← Older revision		Revision as of 02:38, 8 August 2007
Line 1:		Line 1:
	== Simple C++ Math ==		== Simple C++ Math ==

	So, first things first. Lets add the math libraries to our C++ project. That way we have the ability to do useful math functions such as powers, square roots and the like.		So, first things first. Lets add the math libraries to our C++ project. That way we have the ability to do useful math functions such as powers, square roots and the like.

	<code><pre>		<code><pre>
	#include <math>		#include <cmath> // ANSI C++ way. For ANSI C you should do: #include <math.h>
	</pre></code>		</pre></code>

			Note that the math library is one of the 18 ANSI C language standard libraries that can be imported in C++.
	Now you have made many useful functions available to your program. Now, let's do some math.		Now you have made many useful functions available to your program. Now, let's do some math.

Line 29:		Line 30:
	int five=5, six=6, twelve=12;		int five=5, six=6, twelve=12;
	float pi=3.14, myResult;		float pi=3.14, myResult;
	myResult = ~~(float)~~six * pi + (float)twelve;		myResult = six * pi + twelve; // since pi is float, no need to cast six and twelve to float
	myResult = myResult - ~~(float)~~five;		myResult = myResult - five;
	</pre></code>		</pre></code>

Line 66:		Line 67:
	</pre></code>		</pre></code>

	Let's investigate what this does. First, this program takes the square root of 25 and stored into myResult. This leaves a 5.00 in myResult. Then this value is squared and stored back into itself. This means 25.00 will be stored in myResult~~. Notice that I have put 2.00 into the power function. If I was to put just a 2, then the output number would be an integer, and not a float~~. So, more simply:		Let's investigate what this does. First, this program takes the square root of 25 and stored into myResult. This leaves a 5.00 in myResult. Then this value is squared and stored back into itself. This means 25.00 will be stored in myResult. So, more simply:

	<code><pre>		<code><pre>
Line 72:		Line 73:
	</pre></code>		</pre></code>

			For a list of functions, see [http://en.wikipedia.org/wiki/Math.h math.h].
	=== End of lesson 3 ===		=== End of lesson 3 ===