# Feature overview table

Note that all *catch22* features are statistical properties of the *z*-scored time series—they aim to focus on properties of the time-ordering of the data and are insensitive to the raw values in the time series.

In the table below we give the original feature name \[from the Lubba et al. (2019) paper], and a shorter name more suitable for use in feature descriptions.

Features are also (loosely) categorized into broad conceptual groupings.

<table><thead><tr><th width="64" data-type="number">#</th><th width="196">Feature name</th><th width="243">Short name</th><th>Category</th><th>Description</th></tr></thead><tbody><tr><td>1</td><td><code>DN_HistogramMode_5</code></td><td><code>mode_5</code></td><td><a href="/pages/-MfHGJhPR2dozJObe06F">Distribution shape</a></td><td>5-bin histogram mode</td></tr><tr><td>2</td><td><code>DN_HistogramMode_10</code></td><td><code>mode_10</code></td><td><a href="/pages/-MfHGJhPR2dozJObe06F">Distribution shape</a></td><td>10-bin histogram mode</td></tr><tr><td>3</td><td><code>DN_OutlierInclude_p_001_mdrmd</code></td><td><code>outlier_timing_pos</code></td><td><a href="/pages/-MfHL-CI2tYz3kH0NX1U">Extreme event timing</a></td><td>Positive outlier timing</td></tr><tr><td>4</td><td><code>DN_OutlierInclude_n_001_mdrmd</code></td><td><code>outlier_timing_neg</code></td><td><a href="/pages/-MfHL-CI2tYz3kH0NX1U">Extreme event timing</a></td><td>Negative outlier timing</td></tr><tr><td>5</td><td><code>ﬁrst1e_acf_tau</code></td><td><code>acf_timescale</code></td><td><a href="/pages/-MfWOdAGanpG3oYYSZL2">Linear autocorrelation</a></td><td>First <span class="math">1/e</span> crossing of the ACF</td></tr><tr><td>6</td><td><code>ﬁrstMin_acf</code></td><td><code>acf_first_min</code></td><td><a href="/pages/-MfWOdAGanpG3oYYSZL2">Linear autocorrelation</a></td><td>First minimum of the ACF</td></tr><tr><td>7</td><td><code>SP_Summaries_welch_rect_area_5_1</code></td><td><code>low_freq_power</code></td><td><a href="/pages/-MfWOdAGanpG3oYYSZL2">Linear autocorrelation</a></td><td>Power in lowest 20% frequencies </td></tr><tr><td>8</td><td><code>SP_Summaries_welch_rect_centroid</code></td><td><code>centroid_freq</code></td><td><a href="/pages/-MfWOdAGanpG3oYYSZL2">Linear autocorrelation</a></td><td>Centroid frequency</td></tr><tr><td>9</td><td><code>FC_LocalSimple_mean3_stderr</code></td><td><code>forecast_error</code></td><td><a href="/pages/-Mf_42zMdzSOg5ZDXOKp">Simple forecasting</a></td><td>Error of 3-point rolling mean forecast</td></tr><tr><td>10</td><td><code>FC_LocalSimple_mean1_tauresrat</code></td><td><code>whiten_timescale</code></td><td><a href="/pages/shsi4kAkfv6OZhH2QOf6">Incremental differences</a></td><td>Change in autocorrelation timescale after incremental differencing</td></tr><tr><td>11</td><td><code>MD_hrv_classic_pnn40</code></td><td><code>high_fluctuation</code></td><td><a href="/pages/shsi4kAkfv6OZhH2QOf6">Incremental differences</a></td><td>Proportion of high incremental changes in the series</td></tr><tr><td>12</td><td><code>SB_BinaryStats_mean_longstretch1</code></td><td><code>stretch_high</code></td><td><a href="/pages/7bZ6VPDuhCaxwcBovNLN">Symbolic</a></td><td>Longest stretch of above-mean values</td></tr><tr><td>13</td><td><code>SB_BinaryStats_diff_longstretch0</code></td><td><code>stretch_decreasing</code></td><td><a href="/pages/7bZ6VPDuhCaxwcBovNLN">Symbolic</a></td><td>Longest stretch of decreasing values</td></tr><tr><td>14</td><td><code>SB_MotifThree_quantile_hh</code></td><td><code>entropy_pairs</code></td><td><a href="/pages/7bZ6VPDuhCaxwcBovNLN">Symbolic</a></td><td>Entropy of successive pairs in symbolized series</td></tr><tr><td>15</td><td><code>CO_HistogramAMI_even_2_5</code></td><td><code>ami2</code></td><td><a href="/pages/-Mfl3N9Txw35pOHXK8EX">Nonlinear autocorrelation</a></td><td>Histogram-based automutual information (lag 2, 5 bins)</td></tr><tr><td>16</td><td><code>CO_trev_1_num</code></td><td><code>trev</code></td><td><a href="/pages/-Mfl3N9Txw35pOHXK8EX">Nonlinear autocorrelation</a></td><td>Time reversibility</td></tr><tr><td>17</td><td><code>IN_AutoMutualInfoStats_40_gaussian_fmmi</code></td><td><code>ami_timescale</code></td><td><a href="/pages/-Mfl3N9Txw35pOHXK8EX">Nonlinear autocorrelation</a></td><td>First minimum of the AMI function</td></tr><tr><td>18</td><td><code>SB_TransitionMatrix_3ac_sumdiagcov</code></td><td><code>transition_variance</code></td><td><a href="/pages/7bZ6VPDuhCaxwcBovNLN">Symbolic</a></td><td>Transition matrix column variance</td></tr><tr><td>19</td><td><code>PD_PeriodicityWang_th001</code></td><td><code>periodicity</code></td><td><a href="/pages/-MfWOdAGanpG3oYYSZL2">Linear autocorrelation structure</a></td><td>Wang's periodicity metric</td></tr><tr><td>20</td><td><code>CO_Embed2_Dist_tau_d_expfit_meandiff</code></td><td><code>embedding_dist</code></td><td><a href="/pages/OHPbtUVw69lVaklgsKnA">Other</a></td><td>Goodness of exponential fit to embedding distance distribution</td></tr><tr><td>21</td><td><code>SC_FluctAnal_2_rsrangeﬁt_50_1_logi_prop_r1</code></td><td><code>rs_range</code></td><td><a href="/pages/9HRlHT1MHUeqiHFO9nj6">Self-affine scaling</a></td><td>Rescaled range fluctuation analysis (low-scale scaling)</td></tr><tr><td>22</td><td><code>SC_FluctAnal_2_dfa_50_1_2_logi_prop_r1</code></td><td><code>dfa</code></td><td><a href="/pages/9HRlHT1MHUeqiHFO9nj6">Self-affine scaling</a></td><td>Detrended fluctuation analysis (low-scale scaling)</td></tr></tbody></table>

And in some cases, in which scale and spread of the raw time-series values may be relevant to class differences, the two simple distributional moment features (using the `catch24` flag in the software implemenations) can be added:

| Feature name    | Short name | Description        |
| --------------- | ---------- | ------------------ |
| `DN_Mean`       | `mean`     | Mean               |
| `DN_Spread_Std` | `std`      | Standard deviation |


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://time-series-features.gitbook.io/catch22-features/feature-overview-table.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.
