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Data Analysis Programming

esProcSPL edited this page Dec 24, 2024 · 3 revisions

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Novel grid-style programming

Excel-like Grid-style programming

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High Interactivity for Exploratory Analysis

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XLL Plugin Helps Excel

Write SPL code in Excel directly

Finding periods during which stocks have risen consecutively for more than 5 days

=spl("=E(?1).sort(CODE,DT).group@i(CODE!=CODE[-1]||CL<CL[-1]).select(~.len()>=5).conj()",A1:D253)

Concise and Powerful Code

Comprehensive and Simple Operations

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Unique Set and Ordered Operations

calculate the longest consecutive rising days for each stock

SQL

SELECT CODE, MAX(con_rise) AS longest_up_days
FROM (
    SELECT CODE, COUNT(*) AS con_rise
    FROM (
        SELECT CODE, DT,  SUM(updown_flag) OVER (PARTITION BY CODE ORDER BY CODE, DT) AS no_up_days
        FROM (
            SELECT CODE, DT, 
                    CASE WHEN CL > LAG(CL) OVER (PARTITION BY CODE ORDER BY CODE, DT)  THEN 0
                    ELSE 1 END AS updown_flag
            FROM stock
        )
    )
    GROUP BY CODE, no_up_days
)
GROUP BY CODE

Python

import pandas as pd
stock_file = "StockRecords.txt"
stock_info = pd.read_csv(stock_file,sep="\t")
stock_info.sort_values(by=['CODE','DT'],inplace=True)
stock_group = stock_info.groupby(by='CODE')
stock_info['label'] = stock_info.groupby('CODE')['CL'].diff().fillna(0).le(0).astype(int).cumsum()
max_increase_days = {}
for code, group in stock_info.groupby('CODE'):
    max_increase_days[code] = group.groupby('label').size().max() – 1
max_rise_df = pd.DataFrame(list(max_increase_days.items()), columns=['CODE', 'max_increase_days'])

SPL

A
1 StockRecords.xlsx
2 =T(A1).sort(DT)
3 =A2.group(CODE;~.group@i(CL< CL[-1]).max(~.len()):max_increase_days)

Especially skilled at complex scenarios such as order-related operations, sliding windows, and cross-row computations, much simpler than SQL or Python

What to use for data analysis programming: SPL,Python or SPL?


Easy Big Data and Parallel Support

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Lightweight and Portable


Resource

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