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## Eckert IV and VI projection

We conclude the survey of map projections with the Eckert IV and VI projections (-JK), two of several projections used for global thematic maps; They are both equal-area projections whose syntax is

-JK[f|s] lon0/width

where f gives Eckert IV (4) and s (Default) gives Eckert VI (6). The lon0 is the central meridian (which takes precedence over the mid-value implied by the -R setting). A simple Eckert VI world map is thus generated by

    pscoast -R0/360/-90/90 -JKs180/9i -B60g30/30g15 -Dc -A5000 -G180/120/60 \
        -S100/180/255 -W0.25p >! map.ps

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