<div dir="auto">It looks to me that example 11 in this page <a href="https://www.ncl.ucar.edu/Applications/shapefiles.shtml">https://www.ncl.ucar.edu/Applications/shapefiles.shtml</a> does exactly what you want to do, specifically read a shapefile, select an area to mask, save the mask to a netcdf file and then use this variable to mask the original data (i advise you to create the netcdf at first otherwise it will take so much to use the shapefile every time).<div dir="auto"><br></div><div dir="auto">Otherwise you have to explain better what you want to do ;-)</div></div><div class="gmail_extra"><br><div class="gmail_quote">Il 5 mar 2018 11:22 PM, "Leo Niu" <<a href="mailto:leo2018niu@gmail.com">leo2018niu@gmail.com</a>> ha scritto:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">

    

<div>
<div style="line-height:1.6;font-family:'\0082f9\0065b9','\005fae\008f6f\0096c5\009ed1','sans-serif'"><font style="font-size:17px"><br>I'm ploting a contour of an area. But boundries of the interest area in Ncarg4_0 database can't match with my shapefile. I have searched for ploting an area and masking outside using a polyline or polygon shapefile on <a href="http://www.ncl.ucar.edu.But" target="_blank">www.ncl.ucar.edu.But</a> I haven't found a method dealing with this. Is there some ways that can help in ploting contour of an area only inside of a geocoded polygon？<br>Thanks a lot.</font></div><u></u>



    
    
    


<div style="margin:0;padding:0">
    <a href="https://maas.mail.163.com/dashi-web-extend/html/proSignature.html?iconUrl=https://mail-online.nosdn.127.net/qiyelogo/defaultAvatar.png&name=leo2018niu&uid=leo2018niu%40gmail.com&ftlId=3&items=%5B%22%E9%82%AE%E7%AE%B1%EF%BC%9Aleo2018niu%40gmail.com%22%5D" width="400" style="display:block;max-width:400px;background:#fff;padding:15px 0 10px 0;text-decoration:none;outline:none" target="_blank">
        <table cellpadding="0" style="width:100%;max-width:100%;table-layout:fixed;border-collapse:collapse;border-spacing:0;line-height:1.3;color:#9b9ea1;font-size:14px">
            <tbody style="font-family:'PingFang SC','Hiragino Sans GB','WenQuanYi Micro Hei','Microsoft Yahei','\005fae\008f6f\0096c5\009ed1',verdana!important;word-wrap:break-word;word-break:break-all">
                <tr>
                    <td width="45" style="padding:0 7px 0 0;box-sizing:border-box;width:45px">
                        <img width="38" height="38" style="width:38px;height:38px;border-radius:50%" src="https://mail-online.nosdn.127.net/qiyelogo/defaultAvatar.png">
                    </td>
                    <td style="padding:0 0 0 7px">
                        <div style="max-width:380px">
                            <div style="box-sizing:border-box;padding-right:35px;font-size:16px;margin-bottom:5px;color:#31353b;font-weight:bold;width:100%;white-space:nowrap;overflow:hidden;text-overflow:ellipsis">leo2018niu</div>
                            <div style="font-size:0;line-height:0">
                            </div>
                                <div style="word-wrap:break-word;word-break:break-all">
                                    邮箱：leo2018niu@gmail.com
                                </div>
                        </div>
                    </td>
                </tr>
            </tbody>
        </table>
    </a>
</div>

<div style="margin:0"><p style="margin:0;border-top:1px solid #e5e5e5;padding-top:6px;font-size:12px;color:#b6b8bb;line-height:1.5">签名由 <a href="https://mail.163.com/dashi/dlpro.html?from=mail88" style="color:#6aa8f6;text-decoration:none" target="_blank">网易邮箱大师</a> 定制</p></div>
</div>
<br>______________________________<wbr>_________________<br>
ncl-talk mailing list<br>
<a href="mailto:ncl-talk@ucar.edu">ncl-talk@ucar.edu</a><br>
List instructions, subscriber options, unsubscribe:<br>
<a href="http://mailman.ucar.edu/mailman/listinfo/ncl-talk" rel="noreferrer" target="_blank">http://mailman.ucar.edu/<wbr>mailman/listinfo/ncl-talk</a><br>
<br></blockquote></div></div>