FIX: in grdtrack, -Su+d+r gives 0 result

[Dengda98]

bug description

Following command gives 0 value result,

$ gmt grdtrack -G@earth_relief_30m -C23d/0.1/5 -E125/33/146/46+i0.1d -Su+a+d+r+s | head -n5
> Cross profile number -L0-0 at  125.000/033.000 az=-45.1
114.26416966    40.6673817899   -11.503849419   128.406893601   1235.72535495   0       0       0
114.367384391   40.6052116066   -11.403759574   128.406893601   1186.20357679   0       0       0
114.470407141   40.5429497186   -11.3036706902  128.47411274    1138.74642045   0       0       0
114.573238406   40.4805964975   -11.2035827687  128.541121917   1097.87933294   0       0       0

but -Sa(or m or p) result seems fine,

$ gmt grdtrack -G@earth_relief_30m -C23d/0.1/5 -E125/33/146/46+i0.1d -Sa+a+d+r+s | head -n5
> Cross profile number -L0-0 at  125.000/033.000 az=-45.1
114.26416966    40.6673817899   -11.503849419   128.406893601   1235.72535495   720.292586732   470.461540049   515.43276822
114.367384391   40.6052116066   -11.403759574   128.406893601   1186.20357679   671.853133504   467.132268645   514.350443286
114.470407141   40.5429497186   -11.3036706902  128.47411274    1138.74642045   617.656836713   463.490082661   521.089583733
114.573238406   40.4805964975   -11.2035827687  128.541121917   1097.87933294   565.3276248     460.812758913   532.551708144

the stacked profile (stacked_profile.txt, generated by +s) wasn't influenced.

What's Changed

The original continue statement here skip the value assignment, so I changed if to include "envolope" instead.

gmt/src/grdtrack.c

Lines 1018 to 1033 in 1388572

	for (col = 4, colx = col0, k = 0; k < Ctrl->G.n_grids; k++, col++, colx += n_added_cols) { /* Place stacked, deviation, low, high [and lo_env hi_env] for each grid */
	M->data[1+k*n_step][row] = stacked_val[k]; /* The stacked value */
	M->data[2+k*n_step][row] = stacked_dev[k]; /* The stacked deviation */
	M->data[3+k*n_step][row] = stacked_lo[k]; /* The stacked low value */
	M->data[4+k*n_step][row] = stacked_hi[k]; /* The stacked high value */
	if (Ctrl->S.mode >= STACK_LOWER) continue;
	M->data[5+k*n_step][row] = stacked_val[k] - Ctrl->S.factor * stacked_dev[k]; /* The low envelope value */
	M->data[6+k*n_step][row] = stacked_val[k] + Ctrl->S.factor * stacked_dev[k]; /* The low envelope value */
	if (n_added_cols == 0) continue; /* No modification to profile outputs requested */
	for (seg = 0; seg < T->n_segments; seg++) { /* For each segment to append to */
	col_s = colx; /* Start over at this column */
	if (Ctrl->S.selected[STACK_ADD_VAL]) T->segment[seg]->data[col_s++][row] = stacked_val[k]; /* Place stacked value at end of profile */
	if (Ctrl->S.selected[STACK_ADD_DEV]) T->segment[seg]->data[col_s++][row] = stacked_dev[k]; /* Place deviation at end of profile */
	if (Ctrl->S.selected[STACK_ADD_RES]) T->segment[seg]->data[col_s++][row] = T->segment[seg]->data[col][row] - stacked_val[k]; /* Place residuals(s) at end of profile */
	}
	}

The new result seems fine (0 value in residual column is normal for this command),

$ gmt grdtrack -G@earth_relief_30m -C23d/0.1/5 -E125/33/146/46+i0.1d -Su+a+d+r+s | head -n5
> Cross profile number -L0-0 at  125.000/033.000 az=-45.1
114.26416966    40.6673817899   -11.503849419   128.406893601   1235.72535495   1235.72535495   506.723581417   0
114.367384391   40.6052116066   -11.403759574   128.406893601   1186.20357679   1186.20357679   484.533767645   0
114.470407141   40.5429497186   -11.3036706902  128.47411274    1138.74642045   1138.74642045   461.580797293   0
114.573238406   40.4805964975   -11.2035827687  128.541121917   1097.87933294   1097.87933294   439.851354011   0

[joa-quim]

OK, looks good and if it fixes a bad result, fine. Didn't look to any eventual consequences though.