[gnumeric] Add more mass units to CONVERT

[Andreas J. Guelzow <guelzow src gnome org>]

commit 6919aab4e8d04d21aaf5f393531e3be17b0ce86d
Author: Andreas J. Guelzow <aguelzow pyrshep ca>
Date:   Fri Jun 19 21:59:18 2015 -0600

    Add more mass units to CONVERT
    
    2015-06-19  Andreas J. Guelzow <aguelzow pyrshep ca>
    
        * functions.c (gnumeric_convert): add more mass units
        (help_convert): add more mass units

 plugins/fn-eng/ChangeLog   |    5 +++++
 plugins/fn-eng/functions.c |   40 ++++++++++++++++++++++++++++++++++------
 2 files changed, 39 insertions(+), 6 deletions(-)
---
diff --git a/plugins/fn-eng/ChangeLog b/plugins/fn-eng/ChangeLog
index 3825424..09c3446 100644
--- a/plugins/fn-eng/ChangeLog
+++ b/plugins/fn-eng/ChangeLog
@@ -1,3 +1,8 @@
+2015-06-19  Andreas J. Guelzow <aguelzow pyrshep ca>
+
+       * functions.c (gnumeric_convert): add more mass units
+       (help_convert): add more mass units
+
 2015-06-15  Andreas J. Guelzow <aguelzow pyrshep ca>
 
        * functions.c (gnumeric_convert): add PS
diff --git a/plugins/fn-eng/functions.c b/plugins/fn-eng/functions.c
index b78e69d..bc28236 100644
--- a/plugins/fn-eng/functions.c
+++ b/plugins/fn-eng/functions.c
@@ -649,11 +649,22 @@ static GnmFuncHelp const help_convert[] = {
        { GNM_FUNC_HELP_NOTE, F_("If @{from} and @{to} are different types, CONVERT returns #N/A!") },
         { GNM_FUNC_HELP_DESCRIPTION, F_("@{from} and @{to} can be any of the following:\n\n"
                                        "Weight and mass:\n"
+                                       "\t'brton'\t\tImperial ton\n"
+                                       "\t'cwt'\t\t\tU.S. (short) hundredweight\n"
                                        "\t'g'  \t\t\tGram\n"
+                                       "\t'grain'\t\tGrain\n"
+                                       "\t'hweight'\t\tImperial (long) hundredweight\n"
+                                       "\t'LTON'\t\tImperial ton\n"
                                        "\t'sg' \t\t\tSlug\n"
+                                       "\t'shweight'\tU.S. (short) hundredweight\n"
                                        "\t'lbm'\t\tPound\n"
+                                       "\t'lcwt'\t\tImperial  (long) hundredweight\n"
                                        "\t'u'  \t\t\tU (atomic mass)\n"
-                                       "\t'ozm'\t\tOunce\n\n"
+                                       "\t'uk_cwt'\t\tImperial  (long) hundredweight\n"
+                                       "\t'uk_ton'\t\tImperial ton\n"
+                                       "\t'ozm'\t\tOunce\n"
+                                       "\t'stone'\t\tStone\n"
+                                       "\t'ton'\t\t\tTon\n\n"
                                        "Distance:\n"
                                        "\t'm'   \t\tMeter\n"
                                        "\t'mi'  \t\tStatute mile\n"
@@ -672,7 +683,7 @@ static GnmFuncHelp const help_convert[] = {
                                        "\t'mn'  \t\tMinute\n"
                                        "\t'sec' \t\tSecond\n\n"
                                        "Pressure:\n"
-                                       "\t'Pa'  \t\tPascal\n"
+                                       "\t'Pa'  \t\t\tPascal\n"
                                        "\t'atm' \t\tAtmosphere\n"
                                        "\t'mmHg'\t\tmm of Mercury\n\n"
                                        "Force:\n"
@@ -807,10 +818,16 @@ static GnmValue *
 gnumeric_convert (GnmFuncEvalInfo *ei, GnmValue const * const *argv)
 {
         /* Weight and mass constants */
-#define one_g_to_sg     0.00006852205001
-#define one_g_to_lbm    0.002204622915
-#define one_g_to_u      6.02217e+23
-#define one_g_to_ozm    0.035273972
+#define one_g_to_cwt    one_g_to_lbm/100  /* exact relative definition */
+#define one_g_to_grain  one_g_to_lbm*7000 /* exact relative definition */
+#define one_g_to_uk_cwt one_g_to_lbm/112  /* exact relative definition */
+#define one_g_to_uk_ton one_g_to_lbm/2240 /* exact relative definition */
+#define one_g_to_stone  one_g_to_lbm/14   /* exact relative definition */
+#define one_g_to_ton    one_g_to_lbm/2000 /* exact relative definition */
+#define one_g_to_sg     GNM_const (0.00006852205001)
+#define one_g_to_lbm    1/GNM_const (453.59237) /* exact definition */
+#define one_g_to_u      GNM_const (6.02217e+23)
+#define one_g_to_ozm    one_g_to_lbm*16   /* exact relative definition */
 
        /* Distance constants */
 #define one_m_to_mi     (one_m_to_yd / 1760)
@@ -889,10 +906,21 @@ gnumeric_convert (GnmFuncEvalInfo *ei, GnmValue const * const *argv)
 
        static const eng_convert_unit_t weight_units[] = {
                { "g",    1.0 },
+               { "brton",one_g_to_uk_ton },
+               { "cwt",  one_g_to_cwt },
+               { "grain",one_g_to_grain },
+               { "hweight",one_g_to_uk_cwt },
+               { "LTON",one_g_to_uk_ton },
                { "sg",   one_g_to_sg },
+               { "shweight",one_g_to_cwt },
                { "lbm",  one_g_to_lbm },
+               { "lcwt", one_g_to_uk_cwt },
                { "u",    one_g_to_u },
+               { "uk_cwt",one_g_to_uk_cwt },
+               { "uk_ton",one_g_to_uk_ton },
                { "ozm",  one_g_to_ozm },
+               { "stone",one_g_to_stone },
+               { "ton",  one_g_to_ton },
                { NULL,   0.0 }
        };