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Floating point numbers.

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Floating point types.

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Store approximations of real numbers, which in our case can be defined as any number that has a decimal

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point and a fractional part such as 0.3333 or 98.6 or P.

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Although it's not possible to represent an arbitrary real number exactly in computer memory, but it's

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possible to store an approximation.

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So if it seems hard to believe, just think of it like number P, which has infinitely many digits with

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finite computer memory.

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How could you possibly represent infinitely many digits?

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As with all types, floating point types take up a finite amount of memory, which is called the type's

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precision.

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The more precision, a floating point type has, the more accurate it will be.

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Approximation.

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A real number Cplusplus.

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Offer three levels of precision for approximations.

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The first level is plot.

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The second double and a three long double.

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So these levels mean, of course, these are the imaginary levels, but this is the single precision.

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We have the double for double precision.

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Double precision.

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And the next we have the long double for extended precision.

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At precision.

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So as integer types, each floating point representation depends on implementation.

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The section won't go into detail about floating point types, but note that there is substantial nuance

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involved in these implementations.

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On major desktop operating system, the float level usually has four bytes of precision.

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Here.

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Four bytes.

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Uh, the double and long hair levels usually usually have actually eight bytes.

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Eight bytes and long double eight bytes.

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Eight bytes.

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So most users not involved in scientific computing applications can safely ignore the details of floating

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point representation in such cases.

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A good general rule is to use double.

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For those who cannot safely ignore the details, look at the floating point specifications relevant

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to your hardware platform.

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And let's go to floating point literals.

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Floating point literals.

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They are.

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Floating point literals.

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Yeah.

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Wires.

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And yes, the floating point literals are double precision by default.

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If you need a single precision, use an F or uppercase F suffix for extended precision, use L or uppercase

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L, as I will show here float A, for example.

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0.1.

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F double B, for example, 0.2 just A to 0.2.

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We don't need to add any literal or suffix.

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And lastly, long double long double C equals 0.3 L.

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As you can see, we used the uppercase L and uppercase F.

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Actually, let's change the comment here so you can see the codes.

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So.

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And you can also use the scientific notation in literals here.

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Here double, for example, planks.

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Banks constant.

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The Planck's constant.

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The Planck's constant is six point.

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626074004

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and E -34.

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So you might be wondering, what is this, though?

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So no space here are permitted between the significant the base and the suffix, the potential portion

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and the E for 34.

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So that's why we didn't use any suffixes or like any space or literal to use for separation of these

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codes, these values.

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So the floating point format, specifiers, we have format specifiers for printing the these numbers

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on console.

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So the format specifier F displays a float with decimal digits, whereas here e.

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Displays the same number in scientific notation.

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You can let Printf decide which of these two to use with the formats specifier which selects the more

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compact of E or F for double.

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You simply depend on l.

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Lowercase l here to describe desired specifier so for long double you prepend an uppercase l For example,

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if you want to want a double with decimal digits, you will specify lf l or l g.

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Here.

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Now, let me comment here.

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Double.

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With.

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Decimal digits here and.

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New world specifier or here with decimal digits, but for a long double you will you will specify long

80
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double double with decimal digits.

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Here for long double.

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You need to use the uppercase l under under case F and the same uppercase l e or.

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LG.

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So let's write an example code for this and start and compile and run the program, which I will show

85
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you how this format specifiers work on tables.

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00:07:43,120 --> 00:07:47,470
So we have the main command main.

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A function here.

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So we can freely use this as our code.

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So double.

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And here, uh, 6.0.

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221409E 23 which I will explain all of these codes later after compiling and print f.

92
00:08:16,320 --> 00:08:19,560
Uh, for example, Avogadro's number.

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Number is.

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I will explain all of these codes, of course, here.

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L f.

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LG and new line near.

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Then I will give the three three times the same number but with different format specifiers and n.

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N.

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Here and.

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Was this code here?

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00:08:52,740 --> 00:08:56,850
And lastly, let's create the float number

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9.9..

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36.

104
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Here.

105
00:09:06,600 --> 00:09:08,160
Let's print.

106
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Print f.

107
00:09:12,390 --> 00:09:13,320
Hogwarts.

108
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Platform.

109
00:09:20,180 --> 00:09:25,940
Here and e f g new line.

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00:09:26,180 --> 00:09:35,720
Give this use this format, use this number with different formats specified three times HP, HP, HP

111
00:09:36,110 --> 00:09:36,920
and.

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Okay so.

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Imprint.

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And let's finally compile this code here.

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Clear.

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U.S.S. Maine.

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The ship so called, is compiled using the E option.

118
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Let's save this code firstly with Ctrl save and let's compile it again.

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Use this code.

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So.

121
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Okay.

122
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Arson.

123
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Yes.

124
00:10:15,320 --> 00:10:20,750
So as you can see here, let me okay.

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So as you can see here, the first we did the program declares a double here, double called N the format

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specifier.

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The format specifier L e.

128
00:10:37,390 --> 00:10:41,590
Gives you a scientific notation of this number.

129
00:10:41,590 --> 00:10:44,500
So let's see what this first.

130
00:10:45,350 --> 00:10:46,010
Gave us.

131
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This is the scientific notation which we used as E.

132
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Is the scientific notation.

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The program gives us.

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And the second we did here.

135
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Gives the decimal representation of this e n number.

136
00:11:07,810 --> 00:11:13,240
As you can see, this gave us the very long decimal representation of this number.

137
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The last one.

138
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Specifier.

139
00:11:18,510 --> 00:11:24,780
The chooses the scientific notation of these, as you can see here.

140
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This notation gave us almost the same e and number, so.

141
00:11:34,310 --> 00:11:44,210
And here we as you know, we created the plot called each p this produce similar printf output using

142
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the E and F specifiers, as you can see here.

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But the format specifier here.

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Format specifier Here.

145
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Decided to provide the decimal representation of 9.76 rather than the scientific notation.

146
00:12:08,120 --> 00:12:10,700
As a general, you'll use the G.

147
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Print floating point types.

148
00:12:17,790 --> 00:12:21,630
The next lecture will be about the character types.

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And I'm waiting you in the next lecture.