[Qgis-user] Measuring unit of $lenght / Unidad de medida de $lenght
Hola When calculating the length of a line layer ($ lenght), a segment is measured as 0.0599837538499966, but using the measuring tool is 5.8 km. Obviously somewhere I have a configuration problem with the unit of measurement of the $ lenght. Could anyone guide me how to make length measured in miles? (obviously I can make the value is $ lenght x 100 but is not the idea) Cuando calculo el largo de una capa de líneas ($lenght), a un segmento lo mide como de 0.0599837538499966, pero si uso la herramienta medir is 5,8km. Evidentemente en algún lugar tengo un problema de configuración con la unidad de medida de la función $lenght. ¿Alguien podría orientarme como hacer para que length mida en km? (obviamente puedo hacer que el valor sea $lenght x 100 pero no es la idea) Gracias Pablo ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Measuring unit of $lenght / Unidad de medida de $lenght
On 09/20/2012 09:30 AM, Pablo Schweitzer wrote: Hola When calculating the length of a line layer ($ lenght), a segment is measured as 0.0599837538499966, but using the measuring tool is 5.8 km. Obviously somewhere I have a configuration problem with the unit of measurement of the $ lenght. Could anyone guide me how to make length measured in miles? (obviously I can make the value is $ lenght x 100 but is not the idea) Cuando calculo el largo de una capa de líneas ($lenght), a un segmento lo mide como de 0.0599837538499966, pero si uso la herramienta medir is 5,8km. Evidentemente en algún lugar tengo un problema de configuración con la unidad de medida de la función $lenght. ¿Alguien podría orientarme como hacer para que length mida en km? (obviamente puedo hacer que el valor sea $lenght x 100 pero no es la idea) Gracias Pablo The $length calculation is using the native units of the projection (a guess), the Measure Tool is converting to more human readable measurements. You can change between metric and feet in the project properties or QGIS options if you want to get miles. Just look for the measure units choices. I'm not sure if this will change the results of the calculator, for that you might need to multiply by the conversion factor yourself as part of the formula. Thanks, Alex ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Measuring unit of $lenght / Unidad de medida de $lenght
Thanks Alex... Perhaps the unit of measurement is degrees. In Ecuador the circumference of the earth is 40,076 km. 40076/360 ° = 109.79. But the equivalence degrees = km varies with latitude and longitude. So use a conversion factor is very difficult in large countrys lake Argentina :-( In You can change the unit of measure? Thanks Pablo 2012/9/20 Alex Mandel tech_...@wildintellect.com On 09/20/2012 09:30 AM, Pablo Schweitzer wrote: Hola When calculating the length of a line layer ($ lenght), a segment is measured as 0.0599837538499966, but using the measuring tool is 5.8 km. Obviously somewhere I have a configuration problem with the unit of measurement of the $ lenght. Could anyone guide me how to make length measured in miles? (obviously I can make the value is $ lenght x 100 but is not the idea) Cuando calculo el largo de una capa de líneas ($lenght), a un segmento lo mide como de 0.0599837538499966, pero si uso la herramienta medir is 5,8km. Evidentemente en algún lugar tengo un problema de configuración con la unidad de medida de la función $lenght. ¿Alguien podría orientarme como hacer para que length mida en km? (obviamente puedo hacer que el valor sea $lenght x 100 pero no es la idea) Gracias Pablo The $length calculation is using the native units of the projection (a guess), the Measure Tool is converting to more human readable measurements. You can change between metric and feet in the project properties or QGIS options if you want to get miles. Just look for the measure units choices. I'm not sure if this will change the results of the calculator, for that you might need to multiply by the conversion factor yourself as part of the formula. Thanks, Alex ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Measuring unit of $lenght / Unidad de medida de $lenght
Am 20.09.2012 19:37, schrieb Pablo Schweitzer: Thanks Alex... Perhaps the unit of measurement is degrees. In Ecuador the circumference of the earth is 40,076 km. 40076/360 ° = 109.79. But the equivalence degrees = km varies with latitude and longitude. So use a conversion factor is very difficult in large countrys lake Argentina :-( In You can change the unit of measure? It just depends on the Coordinate reference Systems (CRS) you use. WGS84 lat/lon ist in degrees, and most projected CRS are in meters (or feet in some countries). Only Google Mercator has no real unit of mesure. You can have a layer in lat/lon CRS, but the project set to a projected CRS using metres (checking on-the-fly-projection in settings/Project Settings). Measuring is always done in the *project* CRS. Just check out what projected CRS is common in your country. At least UTM (with correct Zone) applies world wide. HTH, Andre Joost ___ Qgis-user mailing list Qgis-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/qgis-user
