extend

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extend [2019/12/04 09:37]
tarquinwj Fixing tip links
extend [2019/12/21 10:00] (current)
tarquinwj Hide is special
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   * They must be followed either by a valid survey **<​station>​** id, or a valid survey **<​leg>​** (pair of stations).\\   * They must be followed either by a valid survey **<​station>​** id, or a valid survey **<​leg>​** (pair of stations).\\
-  * Generally specifying a **<​leg>​** applies the option to ONLY that leg, and specifying a **<​station>​** applies the option to all subsequent **<​legs>​** within the centreline. ​ But there is an exception with hide, and perhaps ignore, so read the notes below carefully.\\+  * Generally specifying a **<​leg>​** applies the option to ONLY that leg, and specifying a **<​station>​** applies the option to both the leg used to reach that station, and all subsequent **<​legs>​** within the centreline. ​ But there is an exception with hide, and perhaps ignore, so read the notes below carefully.\\
   * You can include multiple caves in the same extended elevation, or [[tips#​how_to_export_correct_extended_elevation_from_zig-zag_centerline|straighten out zig-zag surveys]], by way of ''​data nosurvey''​ legs.   * You can include multiple caves in the same extended elevation, or [[tips#​how_to_export_correct_extended_elevation_from_zig-zag_centerline|straighten out zig-zag surveys]], by way of ''​data nosurvey''​ legs.
  
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 ''​extend left <leg> or <​station>''​ - same as for extend right, but extending left!\\ ''​extend left <leg> or <​station>''​ - same as for extend right, but extending left!\\
 \\ \\
-''​extend normal <​leg>''​ - extend this leg only, in the same direction as the leg immediately previous, then continue extending subsequent legs as per leg immediately previous ​[I’m not sure when this is particularly useful! ​ I tend to be explicit, and use right or left in preference to normal and reverse.]\\ +''​extend normal <​leg>''​ - extend this leg only, in the same direction as the leg immediately previous, then continue extending subsequent legs as per leg immediately previous.\\ 
-''​extend normal <​station>''​ - continue generating all extended centreline legs from this station onwards, in the same direction as the leg immediately previous.\\+''​extend normal <​station>''​ - continue generating all extended centreline legs from this station onwards, in the same direction as the leg immediately previous. \\ If extent normal is the first statement after extend start, then it will extend to the right.\\
 ''​extend reverse <​leg>''​ - extend this leg only, in the opposite direction to the leg immediately previous, then continue extending subsequent legs as per leg immediately previous.\\ ''​extend reverse <​leg>''​ - extend this leg only, in the opposite direction to the leg immediately previous, then continue extending subsequent legs as per leg immediately previous.\\
-''​extend reverse <​station>''​ - continue generating all extended centreline legs from this station onwards, in the opposite direction to the leg immediately previous.\\+''​extend reverse <​station>''​ - continue generating all extended centreline legs from this station onwards, in the opposite direction to the leg immediately previous.  \\ If extent reverse is the first statement after extend start, then it will extend to the left.\\
 \\ \\
 ''​extend vertical <​leg>''​ - do not extend this leg horizontally,​ extend only the vertical component of this leg, then continue extending subsequent legs as per leg immediately previous. ​ The order of stations in your vertical statement should usually match the direction of extended elevation centreline generation. However if Therion seems to ignore this vertical statement, try reversing the order of the stations in your vertical statement, and it might work!\\ ''​extend vertical <​leg>''​ - do not extend this leg horizontally,​ extend only the vertical component of this leg, then continue extending subsequent legs as per leg immediately previous. ​ The order of stations in your vertical statement should usually match the direction of extended elevation centreline generation. However if Therion seems to ignore this vertical statement, try reversing the order of the stations in your vertical statement, and it might work!\\
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 ''​extend hide <​station>''​ - hides [the station* and] all leg centrelines (usually two of these) that emanate directly from THIS station. ​ Unlike with other extend options, it does not hide subsequent stations or legs. \\ ''​extend hide <​station>''​ - hides [the station* and] all leg centrelines (usually two of these) that emanate directly from THIS station. ​ Unlike with other extend options, it does not hide subsequent stations or legs. \\
 Note that the centreline generation is carried out as per normal, the stations and legs are just made ‘not visible’.\\ Note that the centreline generation is carried out as per normal, the stations and legs are just made ‘not visible’.\\
 +
 +**Important note:** with ''​left'',​ ''​right'',​ ''​normal'',​ ''​reverse''​ and ''​vertical'',​ Therion and Pocket Topo both apply the selected options to the leg before the station (in whichever direction Therion is traversing the centreline),​ as well as the ones following it - that is to say, it applies it to the leg that creates the station. Survex, on the other hand, applies the selected option to all legs after the selected station. This rare difference from Survex is by design. Because of this, and because it helps clarification too, it is a common approach to specify two lines, one saying to apply the option to the initial leg where it is wanted, and one saying to apply the option to that station. This also avoids some bugs mentioned above.
 +
 +  extend left 3 4
 +  extend left 4
  
 //* Something I don't understand with '​hide'​ above, stations are sometimes hidden, and sometimes not.// //* Something I don't understand with '​hide'​ above, stations are sometimes hidden, and sometimes not.//
  • extend.1575448673.txt.gz
  • Last modified: 7 months ago
  • by tarquinwj