<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div>Hi all,</div><div><br data-mce-bogus="1"></div><div>I'm migrating my C++ code from PROJ4 to PROJ9 and I meet a worrying issue with the computation. Some of my regress tests don't pass so I've tested with cs2cs and gets the same difference:</div><div><br data-mce-bogus="1"></div><div><p style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo;" data-mce-style="caret-color: #000000; color: #000000; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo;"><span class="Apple-converted-space">PROJ4</span></p><p style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo;" data-mce-style="caret-color: #000000; color: #000000; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo;"><span class="Apple-converted-space"> </span>echo<span class="Apple-converted-space"> </span><span class="Object" role="link" id="OBJ_PREFIX_DWT157_com_zimbra_phone" style="color: #005a95; text-decoration: none; cursor: pointer;" data-mce-style="color: #005a95; text-decoration: none; cursor: pointer;"><a href="callto:652760.73700000" style="color: #005a95; text-decoration: none; cursor: pointer;" data-mce-href="callto:652760.73700000" data-mce-style="color: #005a95; text-decoration: none; cursor: pointer;">652760.73700000</a></span><span class="Apple-converted-space"> </span><span class="Object" role="link" id="OBJ_PREFIX_DWT158_com_zimbra_phone" style="color: #005a95; text-decoration: none; cursor: pointer;" data-mce-style="color: #005a95; text-decoration: none; cursor: pointer;"><a href="callto:7033791.24300000 43" style="color: #005a95; text-decoration: none; cursor: pointer;" data-mce-href="callto:7033791.24300000 43" data-mce-style="color: #005a95; text-decoration: none; cursor: pointer;">7033791.24300000 43</a></span>.64200000 | cs2cs +init=IGNF:LAMB93 +to +init=IGNF:RGF93: </p><p style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo;" data-mce-style="caret-color: #000000; color: #000000; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo;">4070327.25<span class="Apple-tab-span" style="white-space: pre;" data-mce-style="white-space: pre;"> </span><span class="Object" role="link" id="OBJ_PREFIX_DWT159_com_zimbra_phone" style="color: #005a95; text-decoration: none; cursor: pointer;" data-mce-style="color: #005a95; text-decoration: none; cursor: pointer;"><a href="callto:166078.93 4891298.61" style="color: #005a95; text-decoration: none; cursor: pointer;" data-mce-href="callto:166078.93 4891298.61" data-mce-style="color: #005a95; text-decoration: none; cursor: pointer;">166078.93 4891298.61</a></span></p><p style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo; min-height: 13px;" data-mce-style="caret-color: #000000; color: #000000; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo; min-height: 13px;"><br></p><p style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo; min-height: 13px;" data-mce-style="caret-color: #000000; color: #000000; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo; min-height: 13px;">PROJ7 or PROJ9</p><p style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo;" data-mce-style="caret-color: #000000; color: #000000; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo;"><span class="Apple-converted-space"> </span>echo<span class="Apple-converted-space"> </span><span class="Object" role="link" id="OBJ_PREFIX_DWT160_com_zimbra_phone" style="color: #005a95; text-decoration: none; cursor: pointer;" data-mce-style="color: #005a95; text-decoration: none; cursor: pointer;"><a href="callto:652760.73700000" style="color: #005a95; text-decoration: none; cursor: pointer;" data-mce-href="callto:652760.73700000" data-mce-style="color: #005a95; text-decoration: none; cursor: pointer;">652760.73700000</a></span><span class="Apple-converted-space"> </span><span class="Object" role="link" id="OBJ_PREFIX_DWT161_com_zimbra_phone" style="color: #005a95; text-decoration: none; cursor: pointer;" data-mce-style="color: #005a95; text-decoration: none; cursor: pointer;"><a href="callto:7033791.24300000 43" style="color: #005a95; text-decoration: none; cursor: pointer;" data-mce-href="callto:7033791.24300000 43" data-mce-style="color: #005a95; text-decoration: none; cursor: pointer;">7033791.24300000 43</a></span>.64200000 | cs2cs +init=IGNF:LAMB93 +to +init=IGNF:RGF93:<span class="Apple-converted-space"> </span></p><p style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo;" data-mce-style="caret-color: #000000; color: #000000; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo;">4070355.05<span class="Apple-tab-span" style="white-space: pre;" data-mce-style="white-space: pre;"> </span><span class="Object" role="link" id="OBJ_PREFIX_DWT162_com_zimbra_phone" style="color: #005a95; text-decoration: none; cursor: pointer;" data-mce-style="color: #005a95; text-decoration: none; cursor: pointer;"><a href="callto:166080.07 4891332.24" style="color: #005a95; text-decoration: none; cursor: pointer;" data-mce-href="callto:166080.07 4891332.24" data-mce-style="color: #005a95; text-decoration: none; cursor: pointer;">166080.07 4891332.24</a></span></p><p style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo;" data-mce-style="caret-color: #000000; color: #000000; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo;"><span class="Object" role="link" style="color: #005a95; text-decoration: none; cursor: pointer;" data-mce-style="color: #005a95; text-decoration: none; cursor: pointer;"><br data-mce-bogus="1"></span></p><p style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo;" data-mce-style="caret-color: #000000; color: #000000; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none; margin: 0px; font-stretch: normal; font-size: 11px; line-height: normal; font-family: menlo;"><span class="Object" role="link" style="color: #005a95; text-decoration: none; cursor: pointer;" data-mce-style="color: #005a95; text-decoration: none; cursor: pointer;"><br data-mce-bogus="1"></span></p></div><div><br data-mce-bogus="1"></div><div>I suspect that PROJ7 and PROJ9 don't read properly the geoid file but I'm not sure. Someone can help me tracking and fixing this problem?</div><div><br>Thanks,</div><div><br data-mce-bogus="1"></div><div>Nicolas Bellaiche</div><div>Institut Géographique National France</div></div></body></html>