Pure Programmer
Project: Compute π
Write a program that computes and prints the value π which can be easily computed with standard math functions using one of the formula:
- atan(1.0)*4.0
- atan2(0.0, -1.0)
- acos(-1.0)
- 2.0*acos(0.0)
Which formula produces an answer closer to the standard math definition of π?
See [[Pi]]
Output
$ rustc ComputePi1.rs
error: unknown format trait `f`
--> ComputePi1.rs:15:37
|
15 | println!("{}", format!("pi1: {0:.15f}", pi1));
| ^
|
= note: the only appropriate formatting traits are:
- ``, which uses the `Display` trait
- `?`, which uses the `Debug` trait
- `e`, which uses the `LowerExp` trait
- `E`, which uses the `UpperExp` trait
- `o`, which uses the `Octal` trait
- `p`, which uses the `Pointer` trait
- `b`, which uses the `Binary` trait
- `x`, which uses the `LowerHex` trait
- `X`, which uses the `UpperHex` trait
error: unknown format trait `f`
--> ComputePi1.rs:17:37
|
17 | println!("{}", format!("pi2: {0:.15f}", pi2));
| ^
|
= note: the only appropriate formatting traits are:
- ``, which uses the `Display` trait
- `?`, which uses the `Debug` trait
- `e`, which uses the `LowerExp` trait
- `E`, which uses the `UpperExp` trait
- `o`, which uses the `Octal` trait
- `p`, which uses the `Pointer` trait
- `b`, which uses the `Binary` trait
- `x`, which uses the `LowerHex` trait
- `X`, which uses the `UpperHex` trait
error: unknown format trait `f`
--> ComputePi1.rs:19:37
|
19 | println!("{}", format!("pi3: {0:.15f}", pi3));
| ^
|
= note: the only appropriate formatting traits are:
- ``, which uses the `Display` trait
- `?`, which uses the `Debug` trait
- `e`, which uses the `LowerExp` trait
- `E`, which uses the `UpperExp` trait
- `o`, which uses the `Octal` trait
- `p`, which uses the `Pointer` trait
- `b`, which uses the `Binary` trait
- `x`, which uses the `LowerHex` trait
- `X`, which uses the `UpperHex` trait
error: unknown format trait `f`
--> ComputePi1.rs:21:37
|
21 | println!("{}", format!("pi4: {0:.15f}", pi4));
| ^
|
= note: the only appropriate formatting traits are:
- ``, which uses the `Display` trait
- `?`, which uses the `Debug` trait
- `e`, which uses the `LowerExp` trait
- `E`, which uses the `UpperExp` trait
- `o`, which uses the `Octal` trait
- `p`, which uses the `Pointer` trait
- `b`, which uses the `Binary` trait
- `x`, which uses the `LowerHex` trait
- `X`, which uses the `UpperHex` trait
error[E0425]: cannot find value `PI` in this scope
--> ComputePi1.rs:16:62
|
16 | println!("{}", format!("abs(pi1 - π): {0:.10e}", fabs(pi1 - PI)));
| ^^ not found in this scope
|
help: consider importing one of these items
|
7 + use consts::PI;
|
7 + use std::f32::consts::PI;
|
error[E0425]: cannot find value `PI` in this scope
--> ComputePi1.rs:18:62
|
18 | println!("{}", format!("abs(pi2 - π): {0:.10e}", fabs(pi2 - PI)));
| ^^ not found in this scope
|
help: consider importing one of these items
|
7 + use consts::PI;
|
7 + use std::f32::consts::PI;
|
error[E0425]: cannot find value `PI` in this scope
--> ComputePi1.rs:20:62
|
20 | println!("{}", format!("abs(pi3 - π): {0:.10e}", fabs(pi3 - PI)));
| ^^ not found in this scope
|
help: consider importing one of these items
|
7 + use consts::PI;
|
7 + use std::f32::consts::PI;
|
error[E0425]: cannot find value `PI` in this scope
--> ComputePi1.rs:22:62
|
22 | println!("{}", format!("abs(pi4 - π): {0:.10e}", fabs(pi4 - PI)));
| ^^ not found in this scope
|
help: consider importing one of these items
|
7 + use consts::PI;
|
7 + use std::f32::consts::PI;
|
warning: unused import: `std::f64::consts`
--> ComputePi1.rs:7:5
|
7 | use std::f64::consts;
| ^^^^^^^^^^^^^^^^
|
= note: `#[warn(unused_imports)]` on by default
error[E0425]: cannot find function `atan` in this scope
--> ComputePi1.rs:10:16
|
10 | let pi1:f64 = atan(1.0f64) * 4.0f64;
| ^^^^ not found in this scope
|
help: use the `.` operator to call the method `atan` on `f64`
|
10 - let pi1:f64 = atan(1.0f64) * 4.0f64;
10 + let pi1:f64 = 1.0f64.atan() * 4.0f64;
|
error[E0425]: cannot find function `atan2` in this scope
--> ComputePi1.rs:11:16
|
11 | let pi2:f64 = atan2(0.0f64,-1.0f64);
| ^^^^^ not found in this scope
|
help: use the `.` operator to call the method `atan2` on `f64`
|
11 - let pi2:f64 = atan2(0.0f64,-1.0f64);
11 + let pi2:f64 = 0.0f64.atan2(-1.0f64);
|
error[E0425]: cannot find function `acos` in this scope
--> ComputePi1.rs:12:16
|
12 | let pi3:f64 = acos(-1.0f64);
| ^^^^ not found in this scope
|
help: use the `.` operator to call the method `acos` on `f64`
|
12 | let pi3:f64 = (-1.0f64).acos();
| ~ ~~~~~~~~
error[E0425]: cannot find function `acos` in this scope
--> ComputePi1.rs:13:25
|
13 | let pi4:f64 = 2.0f64 * acos(0.0f64);
| ^^^^ not found in this scope
|
help: use the `.` operator to call the method `acos` on `f64`
|
13 - let pi4:f64 = 2.0f64 * acos(0.0f64);
13 + let pi4:f64 = 2.0f64 * 0.0f64.acos();
|
error[E0425]: cannot find function `fabs` in this scope
--> ComputePi1.rs:16:51
|
16 | println!("{}", format!("abs(pi1 - π): {0:.10e}", fabs(pi1 - PI)));
| ^^^^ not found in this scope
error[E0425]: cannot find function `fabs` in this scope
--> ComputePi1.rs:18:51
|
18 | println!("{}", format!("abs(pi2 - π): {0:.10e}", fabs(pi2 - PI)));
| ^^^^ not found in this scope
error[E0425]: cannot find function `fabs` in this scope
--> ComputePi1.rs:20:51
|
20 | println!("{}", format!("abs(pi3 - π): {0:.10e}", fabs(pi3 - PI)));
| ^^^^ not found in this scope
error[E0425]: cannot find function `fabs` in this scope
--> ComputePi1.rs:22:51
|
22 | println!("{}", format!("abs(pi4 - π): {0:.10e}", fabs(pi4 - PI)));
| ^^^^ not found in this scope
error: aborting due to 16 previous errors; 1 warning emitted
For more information about this error, try `rustc --explain E0425`.