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Challenges Evaluate a single variable polynomial equation

Challenge Given a list of n numbers and x, compute $a + bx^1 + cx^{2} + ... + zx^{n-1}$, where a is the first value in the list, b is the second, etc. n is at most 256 and at least 0. The input va...

20 answers · posted 6y ago by moony‭ · last activity 4y ago by south‭

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#4: Post edited by

user‭ · 2021-08-17T22:15:23Z (about 5 years ago)
Use [] because it wasn't clear where the list ended and where x was

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Evaluate a single variable polynomial equation

# Challenge
Given a list of n numbers and x, compute $a + bx^1 + cx^{2} + ... + zx^{n-1}$, where a is the first value in the list, b is the second, etc. n is at most 256 and at least 0. The input value(s) can be any 32-bit float
Input can be in any format of choice, as long as it is a list of numbers and x. (And this'll likely stay this way, even if input rules change over time)
# Test inputs
~~`1.0`, `182` -> `1` ~~
~~`1.0, 2.0`, `4` -> `9` ~~
~~`2.5, 2.0`, `0.5` -> `3.5` ~~
~~`1.0, 2.0, 3.0, 4.0`, `1.5` -> `24.25` ~~
# Example ungolfed program (Rust)
```rust
// dbg! is a logging function, prints the expression and it's output.
// Good for seeing what's happening
// Test setup
pub fn main() {
let inp: &[f32] = &[1.0, 2.0, 3.0, 4.0];
let x: f32 = 1.5;
dbg!(evaluate_polynomial(inp, x)); // take inputs, print result
}
// Actual challenge answer function
pub fn evaluate_polynomial(inp: &[f32], x: f32) -> f32 {
let mut accum: f32 = 0.0;
for (idx, val) in inp.iter().enumerate() {
// x.pow(idx) * val
accum += dbg!(x.powf(idx as f32) * val);
}
return accum;
}
```

# Challenge
Given a list of n numbers and x, compute $a + bx^1 + cx^{2} + ... + zx^{n-1}$, where a is the first value in the list, b is the second, etc. n is at most 256 and at least 0. The input value(s) can be any 32-bit float
Input can be in any format of choice, as long as it is a list of numbers and x. (And this'll likely stay this way, even if input rules change over time)
# Test inputs
`[1.0]`, `182` -> `1`
`[1.0, 2.0]`, `4` -> `9`
`[2.5, 2.0]`, `0.5` -> `3.5`
`[1.0, 2.0, 3.0, 4.0]`, `1.5` -> `24.25`
# Example ungolfed program (Rust)
```rust
// dbg! is a logging function, prints the expression and it's output.
// Good for seeing what's happening
// Test setup
pub fn main() {
let inp: &[f32] = &[1.0, 2.0, 3.0, 4.0];
let x: f32 = 1.5;
dbg!(evaluate_polynomial(inp, x)); // take inputs, print result
}
// Actual challenge answer function
pub fn evaluate_polynomial(inp: &[f32], x: f32) -> f32 {
let mut accum: f32 = 0.0;
for (idx, val) in inp.iter().enumerate() {
// x.pow(idx) * val
accum += dbg!(x.powf(idx as f32) * val);
}
return accum;
}
```

#3: Post edited by

moony‭ · 2020-11-15T07:02:51Z (almost 6 years ago)

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# Challenge
Given a list of n numbers and x, compute $a + bx^1 + cx^{2} + ... + zx^{n-1}$, where a is the first value in the list, b is the second, etc. n is at most 256 and at least 0. The input value(s) can be any 32-bit float
Input can be in any format of choice, as long as it is a list of numbers and x. (And this'll likely stay this way, even if input rules change over time)
# Test inputs
`1.0`, `182` -> `1`
`1.0, 2.0`, `4` -> `9`
`2.5, 2.0`, `0.5` -> `3.5`
~~`1.0, 2.0, 3.0, 4.0`, `1.5` -> `24.25 ~~
# Example ungolfed program (Rust)
```rust
// dbg! is a logging function, prints the expression and it's output.
// Good for seeing what's happening
// Test setup
pub fn main() {
let inp: &[f32] = &[1.0, 2.0, 3.0, 4.0];
let x: f32 = 1.5;
dbg!(evaluate_polynomial(inp, x)); // take inputs, print result
}
// Actual challenge answer function
pub fn evaluate_polynomial(inp: &[f32], x: f32) -> f32 {
let mut accum: f32 = 0.0;
for (idx, val) in inp.iter().enumerate() {
// x.pow(idx) * val
accum += dbg!(x.powf(idx as f32) * val);
}
return accum;
}
```

# Challenge
Given a list of n numbers and x, compute $a + bx^1 + cx^{2} + ... + zx^{n-1}$, where a is the first value in the list, b is the second, etc. n is at most 256 and at least 0. The input value(s) can be any 32-bit float
Input can be in any format of choice, as long as it is a list of numbers and x. (And this'll likely stay this way, even if input rules change over time)
# Test inputs
`1.0`, `182` -> `1`
`1.0, 2.0`, `4` -> `9`
`2.5, 2.0`, `0.5` -> `3.5`
`1.0, 2.0, 3.0, 4.0`, `1.5` -> `24.25`
# Example ungolfed program (Rust)
```rust
// dbg! is a logging function, prints the expression and it's output.
// Good for seeing what's happening
// Test setup
pub fn main() {
let inp: &[f32] = &[1.0, 2.0, 3.0, 4.0];
let x: f32 = 1.5;
dbg!(evaluate_polynomial(inp, x)); // take inputs, print result
}
// Actual challenge answer function
pub fn evaluate_polynomial(inp: &[f32], x: f32) -> f32 {
let mut accum: f32 = 0.0;
for (idx, val) in inp.iter().enumerate() {
// x.pow(idx) * val
accum += dbg!(x.powf(idx as f32) * val);
}
return accum;
}
```

#2: Post edited by

xnor‭ · 2020-11-13T23:10:23Z (almost 6 years ago)

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# Challenge
Given a list of n numbers and x, compute $a + bx^1 + cx^{2} + zx^{n-1}$, where a is the first value in the list, b is the second, etc. n is at most 256 and at least 0. The input value(s) can be any 32-bit float
Input can be in any format of choice, as long as it is a list of numbers and x. (And this'll likely stay this way, even if input rules change over time)
# Test inputs
`1.0`, `182` -> `1`
`1.0, 2.0`, `4` -> `9`
`2.5, 2.0`, `0.5` -> `3.5`
`1.0, 2.0, 3.0, 4.0`, `1.5` -> `24.25
# Example ungolfed program (Rust)
```rust
// dbg! is a logging function, prints the expression and it's output.
// Good for seeing what's happening
// Test setup
pub fn main() {
let inp: &[f32] = &[1.0, 2.0, 3.0, 4.0];
let x: f32 = 1.5;
dbg!(evaluate_polynomial(inp, x)); // take inputs, print result
}
// Actual challenge answer function
pub fn evaluate_polynomial(inp: &[f32], x: f32) -> f32 {
let mut accum: f32 = 0.0;
for (idx, val) in inp.iter().enumerate() {
// x.pow(idx) * val
accum += dbg!(x.powf(idx as f32) * val);
}
return accum;
}
```

# Challenge
Given a list of n numbers and x, compute $a + bx^1 + cx^{2} + ... + zx^{n-1}$, where a is the first value in the list, b is the second, etc. n is at most 256 and at least 0. The input value(s) can be any 32-bit float
Input can be in any format of choice, as long as it is a list of numbers and x. (And this'll likely stay this way, even if input rules change over time)
# Test inputs
`1.0`, `182` -> `1`
`1.0, 2.0`, `4` -> `9`
`2.5, 2.0`, `0.5` -> `3.5`
`1.0, 2.0, 3.0, 4.0`, `1.5` -> `24.25
# Example ungolfed program (Rust)
```rust
// dbg! is a logging function, prints the expression and it's output.
// Good for seeing what's happening
// Test setup
pub fn main() {
let inp: &[f32] = &[1.0, 2.0, 3.0, 4.0];
let x: f32 = 1.5;
dbg!(evaluate_polynomial(inp, x)); // take inputs, print result
}
// Actual challenge answer function
pub fn evaluate_polynomial(inp: &[f32], x: f32) -> f32 {
let mut accum: f32 = 0.0;
for (idx, val) in inp.iter().enumerate() {
// x.pow(idx) * val
accum += dbg!(x.powf(idx as f32) * val);
}
return accum;
}
```

#1: Initial revision by

moony‭ · 2020-11-13T22:53:25Z (almost 6 years ago)

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Evaluate a single variable polynomial equation

# Challenge

Given a list of n numbers and x, compute $a + bx^1 + cx^{2} +  zx^{n-1}$, where a is the first value in the list, b is the second, etc. n is at most 256 and at least 0. The input value(s) can be any 32-bit float

Input can be in any format of choice, as long as it is a list of numbers and x. (And this'll likely stay this way, even if input rules change over time)
# Test inputs
`1.0`, `182` -> `1`<br/>
`1.0, 2.0`, `4` -> `9`<br/>
`2.5, 2.0`, `0.5` -> `3.5`<br/>
`1.0, 2.0, 3.0, 4.0`, `1.5` -> `24.25<br/>

# Example ungolfed program (Rust)
```rust
// dbg! is a logging function, prints the expression and it's output.
// Good for seeing what's happening

// Test setup
pub fn main() {
    let inp: &[f32] = &[1.0, 2.0, 3.0, 4.0];
    let x: f32 = 1.5;
    dbg!(evaluate_polynomial(inp, x)); // take inputs, print result	
}

// Actual challenge answer function
pub fn evaluate_polynomial(inp: &[f32], x: f32) -> f32 {
    let mut accum: f32 = 0.0;

    for (idx, val) in inp.iter().enumerate() {
        // x.pow(idx) * val
        accum += dbg!(x.powf(idx as f32) * val);
    }

    return accum;
}
```

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