use anyhow::Result;
use polars::prelude::*;
use std::path::Path;
pub fn summarize(df: &DataFrame, columns: &[String]) -> Result<String> {
let df = select_columns(df, columns)?;
let mut result = String::new();
result.push_str("## Dataset Summary\n\n");
result.push_str(&format!("Shape: {} rows × {} columns\n\n", df.height(), df.width()));
result.push_str("### Columns\n\n");
for field in df.schema().iter_fields() {
result.push_str(&format!("- `{}`: {}\n", field.0, field.1));
}
result.push_str("\n");
result.push_str("### Descriptive Statistics\n\n");
match df.describe(None) {
Ok(stats) => {
result.push_str(&format!("{}\n", stats));
},
Err(e) => {
result.push_str(&format!("Error calculating statistics: {}\n", e));
}
}
result.push_str("\n### Missing Values\n\n");
for col in df.get_column_names() {
let null_count = df.column(col)?.null_count();
let percent = (null_count as f64 / df.height() as f64) * 100.0;
result.push_str(&format!("- `{}`: {} ({:.2}%)\n", col, null_count, percent));
}
Ok(result)
}
pub fn calculate_correlations(df: &DataFrame, columns: &[String]) -> Result<String> {
let df = select_columns(df, columns)?;
let numeric_cols: Vec<_> = df.get_column_names().iter()
.filter(|&col| matches!(df.column(col).unwrap().dtype(), DataType::Float64 | DataType::Int64))
.map(|&s| s.to_string())
.collect();
if numeric_cols.is_empty() {
return Ok("No numeric columns found for correlation analysis.".to_string());
}
let mut result = String::new();
result.push_str("## Correlation Analysis\n\n");
match df.select(&numeric_cols).unwrap().corr() {
Ok(corr_matrix) => {
result.push_str(&format!("{}\n", corr_matrix));
},
Err(e) => {
result.push_str(&format!("Error calculating correlation matrix: {}\n", e));
}
}
Ok(result)
}
pub fn cluster_data(df: &DataFrame, columns: &[String]) -> Result<String> {
let df = select_columns(df, columns)?;
let mut result = String::new();
result.push_str("## Clustering Analysis\n\n");
result.push_str("This is a placeholder for clustering analysis.\n");
result.push_str("In a real implementation, this would perform k-means or other clustering algorithms.\n");
result.push_str("\nSample code to implement with linfa would be:\n\n");
result.push_str("```rust\n");
result.push_str("use linfa::prelude::*;\n");
result.push_str("use linfa_clustering::{KMeans, KMeansParams};\n\n");
result.push_str("// Prepare data as a Dataset\n");
result.push_str("let dataset = ...; // Convert DataFrame to Dataset\n\n");
result.push_str("// Run k-means with k=3\n");
result.push_str("let model = KMeans::params(3)\n");
result.push_str(" .max_n_iterations(100)\n");
result.push_str(" .tolerance(1e-5)\n");
result.push_str(" .fit(&dataset)?;\n\n");
result.push_str("// Get cluster assignments\n");
result.push_str("let predictions = model.predict(&dataset);\n");
result.push_str("```\n");
Ok(result)
}
pub fn analyze_timeseries(df: &DataFrame, columns: &[String]) -> Result<String> {
let df = select_columns(df, columns)?;
let mut result = String::new();
result.push_str("## Time Series Analysis\n\n");
let datetime_cols: Vec<_> = df.get_column_names().iter()
.filter(|&col| {
matches!(df.column(col).unwrap().dtype(),
DataType::Date | DataType::Datetime(_, _))
})
.map(|&s| s.to_string())
.collect();
if datetime_cols.is_empty() {
result.push_str("No datetime columns found for time series analysis.\n");
} else {
result.push_str(&format!("Found {} datetime columns: {}\n\n",
datetime_cols.len(),
datetime_cols.join(", ")));
result.push_str("This is a placeholder for time series analysis.\n");
result.push_str("In a real implementation, this would perform trend analysis, seasonality decomposition, and forecasting.\n");
}
Ok(result)
}
pub fn visualize(df: &DataFrame, columns: &[String], output_path: &Path) -> Result<()> {
use plotters::prelude::*;
let df = select_columns(df, columns)?;
let root = BitMapBackend::new(output_path, (800, 600)).into_drawing_area();
root.fill(&WHITE)?;
let mut chart_builder = ChartBuilder::on(&root)
.caption("Data Visualization", ("sans-serif", 40))
.margin(10)
.x_label_area_size(30)
.y_label_area_size(30);
let numeric_cols: Vec<_> = df.get_column_names().iter()
.filter(|&col| matches!(df.column(col).unwrap().dtype(), DataType::Float64 | DataType::Int64))
.map(|&s| s.to_string())
.collect();
if numeric_cols.len() < 2 {
if numeric_cols.len() == 1 {
let col_name = &numeric_cols[0];
let series = df.column(col_name)?.i64()?;
let mut chart = chart_builder
.build_cartesian_2d(0..series.len() as i32, 0..*series.max()? as i32 + 10)?;
chart.configure_mesh().draw()?;
chart.draw_series(
Histogram::vertical(&chart)
.style(BLUE.filled())
.data(series.iter().enumerate().map(|(i, v)| (i as i32, v.unwrap_or(0))))
)?;
chart.configure_series_labels().draw()?;
} else {
root.draw_text(
"No numeric columns available for visualization",
&TextStyle::from(("sans-serif", 20)).color(&BLACK),
(400, 300),
)?;
}
} else {
let x_col = &numeric_cols[0];
let y_col = &numeric_cols[1];
let x_series = df.column(x_col)?.f64()?;
let y_series = df.column(y_col)?.f64()?;
let x_min = *x_series.min()? - 1.0;
let x_max = *x_series.max()? + 1.0;
let y_min = *y_series.min()? - 1.0;
let y_max = *y_series.max()? + 1.0;
let mut chart = chart_builder
.build_cartesian_2d(x_min..x_max, y_min..y_max)?;
chart.configure_mesh()
.x_desc(x_col)
.y_desc(y_col)
.draw()?;
let points: Vec<_> = x_series.iter()
.zip(y_series.iter())
.filter_map(|(x, y)| match (x, y) {
(Some(x), Some(y)) => Some((*x, *y)),
_ => None,
})
.collect();
chart.draw_series(
points.iter().map(|point| Circle::new(*point, 3, BLUE.filled()))
)?;
chart.configure_series_labels()
.background_style(WHITE.mix(0.8))
.border_style(BLACK)
.draw()?;
}
root.present()?;
Ok(())
}
fn select_columns(df: &DataFrame, columns: &[String]) -> Result<DataFrame> {
if columns.is_empty() {
Ok(df.clone())
} else {
let available_cols: Vec<_> = columns.iter()
.filter(|col| df.get_column_names().contains(&col.as_str()))
.map(|s| s.as_str())
.collect();
if available_cols.is_empty() {
Ok(df.clone())
} else {
Ok(df.select(&available_cols)?)
}
}
}