---
name: "Math::NumSeq::PlanePathN"
section: "3pm"
platform: "linux"
package: "libmath-planepath-perl"
version: "129-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Math::NumSeq::PlanePathN"
---

# Math::NumSeq::PlanePathN(3pm)

## NAME

Math::NumSeq::PlanePathN -- sequence of N values from PlanePath module

## SYNOPSIS

```
 use Math::NumSeq::PlanePathN;
 my $seq = Math::NumSeq::PlanePathN->new (planepath => 'SquareSpiral',
                                          line_type => 'X_axis');
 my ($i, $value) = $seq->next;
```

## DESCRIPTION

This module presents N values from a `"Math::PlanePath"` as a sequence.  The default is the X axis, or the `"line_type"` parameter (a string) can choose among

```
    "X_axis"        X axis (positive part)
    "Y_axis"        Y axis (positive part)
    "X_neg"         X negative axis
    "Y_neg"         Y negative axis
    "Diagonal"      leading diagonal X=i, Y=i
    "Diagonal_NW"   north-west diagonal X=-i, Y=i
    "Diagonal_SW"   south-west diagonal X=-i, Y=-i
    "Diagonal_SE"   south-east diagonal X=i, Y=-i
    "Depth_start"   first N at depth=i
    "Depth_end"     last N at depth=i
```

For example the `"SquareSpiral"` X axis starts i=0 with values 1, 2, 11, 28, 53, 86, etc.

"X\_neg", "Y\_neg", "Diagonal\_NW", etc, on paths which don't traverse negative X or Y have just a single value from X=0,Y=0.

The behaviour on paths which visit only some of the points on the respective axis is unspecified as yet, as is behaviour on paths with repeat points, such as the `"DragonCurve"`.

## FUNCTIONS

See "FUNCTIONS" in Math::NumSeq for behaviour common to all sequence classes.

- "$seq = Math::NumSeq::PlanePathN-\>new (key=\>value,...)"

  Create and return a new sequence object.  The options are

  ```
      planepath          string, name of a PlanePath module
      planepath_object   PlanePath object
      line_type          string, as described above
  ```

  `"planepath"` can be either the module part such as "SquareSpiral" or a full class name "Math::PlanePath::SquareSpiral".

- "$value = $seq-\>ith($i)"

  Return the N value at `$i` in the PlanePath.  `$i` gives a position on the respective `"line_type"`, so the X,Y to lookup a `"$value=N"` is

  ```
       X,Y       line_type
      -----      ---------
      $i, 0      "X_axis"
      0, $i      "Y_axis"
      -$i, 0     "X_neg"
      0, -$i     "Y_neg"
      $i, $i     "Diagonal"
      $i, -$i    "Diagonal_NW"
      -$i, -$i   "Diagonal_SW"
      $i, -$i    "Diagonal_SE"
  ```

- "$bool = $seq-\>pred($value)"

  Return true if `$value` occurs in the sequence.

  This means `$value` is an integer N which is on the respective `"line_type"`, ie. that `"($path->n_to_xy($value)"` is on the line type.

## SEE ALSO

Math::NumSeq, Math::NumSeq::PlanePathCoord, Math::NumSeq::PlanePathDelta

## HOME PAGE

\<http://user42.tuxfamily.org/math-planepath/index.html\>

## LICENSE

Copyright 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019, 2020, 2021 Kevin Ryde

This file is part of Math-PlanePath.

Math-PlanePath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.

Math-PlanePath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with Math-PlanePath.  If not, see \<http://www.gnu.org/licenses/\>.