csc.analysisRun.computeCSC

Inputs

curve

Scalar DTA curve struct. curve.headers must contain the exact names T, Vf, and Im, and curve.data must hold the corresponding numeric columns. T is in seconds, Vf in volts, and Im in amperes.

opts

Optional scalar struct described below. Default: struct().

Options

scanRate

Positive finite voltage scan rate in V/s. This value is required for the CV-derived charge. Default: NaN, which returns ok=false.

mode

Charge branch reported in Qct and Qcv: "Full", "Cathodic", or "Anodic". Unrecognized values use "Full". Default: "Full".

area_cm2

Positive electrode area in cm^2 as a numeric scalar or numeric text. Invalid or missing values leave density fields NaN while charge calculations still succeed. Default: NaN.

Outputs

A

Scalar result struct. On success, it contains every field described below. Validation failures return ok=false, a stable message and logMessage, plus the option fields established before the failure.

Result Fields

ok

Logical success flag.

message

"OK", "scan rate missing", "Need T, Vf, Im", or "Not enough points".

logMessage

User-facing explanation for a failed comparison; blank on success.

mode

Effective branch used for Qct and Qcv.

scanRate

Effective scan rate in V/s.

area_cm2

Parsed positive electrode area, or NaN.

t

Filtered time vector in seconds.

Vf

Filtered voltage vector in volts.

Im

Filtered current vector in amperes.

IcathDisp

Im with zero and anodic samples replaced by NaN.

IanodDisp

Im with zero and cathodic samples replaced by NaN.

QctCath

Absolute cathodic integral of I dt in coulombs.

QctAnod

Anodic integral of I dt in coulombs.

QctFull

QctCath + QctAnod in coulombs.

QcvCath

Absolute cathodic scan-rate-derived charge in coulombs.

QcvAnod

Anodic scan-rate-derived charge in coulombs.

QcvFull

QcvCath + QcvAnod in coulombs.

Qct

QctCath, QctAnod, or QctFull selected by mode.

Qcv

QcvCath, QcvAnod, or QcvFull selected by mode.

diff_C

Signed difference Qct-Qcv in coulombs.

rel_pct

100*abs(diff_C)/max(abs(Qct),abs(Qcv)); zero when both selected charges are zero.

dtErr

Largest absolute difference, in seconds, between each measured time interval and abs(dV)/scanRate after zero-crossing subdivision.

Qct_mC_cm2

Selected CT charge density in mC/cm^2, or NaN without area.

Qcv_mC_cm2

Selected CV charge density in mC/cm^2, or NaN without area.

diff_mC_cm2

Signed density difference in mC/cm^2, or NaN without area.

Description

computeCSC evaluates one current-voltage cycle two ways. The CT result uses recorded time, while the CV result reconstructs interval duration from the commanded scan rate. Reporting both values makes timing inconsistencies and charge-density differences visible without requiring the CSC GUI.

Calculations

Rows containing NaN in T, Vf, or Im are removed together. Each adjacent sample interval is split where linearly interpolated current crosses zero. CT charge integrates current over measured time. CV charge uses dt=abs(dV)/scanRate for the same current endpoints. Cathodic contributions are stored as positive magnitudes, so each full charge is the sum of two nonnegative phase charges.

Failure Behavior

A missing scan rate, missing exact column name, or fewer than two remaining samples returns ok=false instead of throwing. Malformed MATLAB types or inconsistent curve dimensions may still raise an indexing or numeric error.

Example

curve = struct("headers", {{'T','Vf','Im'}}, ...
"data", [0 0 -1; 1 1 1; 2 2 1]);
A = csc.analysisRun.computeCSC(curve, ...
struct("scanRate", 2, "mode", "Full"));
assert(A.ok && abs(A.QctFull - 1.5) < 1e-12)