trend-analysis

trend-analysis is a skill for Claude Code, Codex from danielrosehill/Claude-Data-Analyst-plugin. It costs 52 tokens per session (751 once invoked), scanned A, original, MIT.

An analysis that explains the main patterns in data over time, such as increases, decreases, growth rates, seasonal repetition, and changes between groups. Seasonality means a pattern that repeats at regular periods, such as weekly or yearly.

In plain words
What is it for?
Use it on datasets with dates and numeric measures, optionally focusing on selected metrics or breaking results down by a segment such as region or product.
Why use it?
It turns time-based measurements into a plain-language account of what is changing and where, instead of leaving you to interpret tables alone.

Skill for Claude CodeCodex

Part of the claude-data-analyst plugin — 14 skills shipped together

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/danielrosehill/claude-data-analyst-plugin/trend-analysis
Any agent
npx skills add danielrosehill/Claude-Data-Analyst-plugin --skill trend-analysis
Clone the repo
git clone --depth 1 https://github.com/danielrosehill/Claude-Data-Analyst-plugin

Made for: Claude Code, Codex.

Or install claude-data-analyst, the plugin that ships this one along with the rest of its 14 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for trend-analysis

README.md
[![agentmods](https://agentmods.dev/badge/skills/danielrosehill/claude-data-analyst-plugin/trend-analysis.svg)](https://agentmods.dev/skills/danielrosehill/claude-data-analyst-plugin/trend-analysis)
Your own site
<a href="https://agentmods.dev/skills/danielrosehill/claude-data-analyst-plugin/trend-analysis"><img src="https://agentmods.dev/badge/skills/danielrosehill/claude-data-analyst-plugin/trend-analysis.svg" alt="Measured on agentmods" height="20"></a>
Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 751 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00052 $0.00751
Opus 5 $0.00026 $0.00376
Sonnet 5 $0.00010 $0.00150
Haiku 4.5 $0.00005 $0.00075

Measured 5d ago against content hash 77674018ceb1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

trend-analysis scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/trend-analysis/SKILL.md · 67 lines

How it starts

The opening of the file, as written. The whole thing — 67 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Trend Analysis

Identify the major trends in a dataset and summarise them in a narrative report.

Inputs

  • Path to a dataset file or folder.
  • Optional: time column name (auto-detected if a single date/datetime column exists).
  • Optional: metric(s) of interest — numeric columns to focus trend analysis on. Default: all numerics.
  • Optional: segment column — to produce per-segment trend breakdowns.
  • duckdb — windowed SQL aggregations (time_bucket, moving averages, YoY).
  • uv run --with pandas --with statsmodels python -c '...' — STL decomposition, Mann-Kendall trend test, seasonal detection.
  • mlr (miller) — quick pivots and tallies on CSV without loading pandas.

Procedure

Step 1 — Temporal trends (if time column exists)

For each metric:

  • Overall direction: fit linear regression on the metric vs. time. Report slope, R², and sign (up/down/flat). Supplement with Mann-Kendall test for monotonic trend (robust to outliers and non-linearity).
  • Growth rate: first-to-last period % change, and CAGR if span > 1 year.
  • Level shifts / change points: detect structural breaks (PELT or simple rolling mean comparison).
  • Seasonality: if ≥2 seasonal cycles present, run STL decomposition and report dominant period (weekly, monthly, yearly).
  • Recency: compare last period vs. trailing average — is the trend accelerating, decelerating, or reversing?

Step 2 — Compositional trends (categorical)

For each categorical column:

  • Which categories are growing in share over time?
  • Which are shrinking?
  • Any new entrants appearing only in recent periods?
  • Any categories that disappeared?

Step 3 — Segment trends

If a segment column is provided, repeat Step 1 within each segment and surface:

  • Segments with the strongest growth / decline
  • Segments diverging from the overall trend (Simpson's-paradox watchlist)

Step 4 — Non-temporal trends

If no time column exists, "trend" becomes distributional:

  • Skew, concentration (top-N share, Gini), long-tail structure
  • Dominant vs. rare categories
  • Relationships between paired columns (lean on correlation-analysis for the heavy lifting; summarise headlines only)

Read the full file on GitHub · 67 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 67 lines · 52 tokens per session scan A 77674018ceb1

Subscribe to this mod's changes

trend-analysis is a skill published in the GitHub repository danielrosehill/Claude-Data-Analyst-plugin (11 stars, last pushed 4mo ago), licensed MIT. It adds 52 tokens to every session and 751 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other skills, from other repositories